diff --git a/research/minimum-root-row-prefix/CONSUMER-INVENTORY.json b/research/minimum-root-row-prefix/CONSUMER-INVENTORY.json
new file mode 100644
index 0000000000..afc6e4335a
--- /dev/null
+++ b/research/minimum-root-row-prefix/CONSUMER-INVENTORY.json
@@ -0,0 +1,190 @@
+[
+  {
+    "path": "research/physical-complex-controller/bank_packets.py",
+    "sha256": "83e2f80fb72c906ccc7857f2b5139758ca8a997b17f51a5db29e2bb3c1143477",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_bank.py",
+    "sha256": "6a5cd81ad980565c06f9e0df8c81eb6946dc69caf3704ee5b233ebdef6fb83c5",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_bounds.py",
+    "sha256": "697606202fbef8463f6ee736007b9630c55034246dcda17c23b03e97d270dcc7",
+    "consumer_tokens": [
+      "stock"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/check_cover.py",
+    "sha256": "d50271a051d9d944dd7a5541756b508c8b19248d8d37bd30e729aaf7210435fd",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_failures.py",
+    "sha256": "785e9ff582aad9a6cee7cf339134309a863c8d4fa79367c31b2cc03b31282a5f",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_grid.py",
+    "sha256": "a08092d0bbcbb69459d936e2f6f7f431134cba9c31ffdc173c82878d00ea98e3",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_machine.py",
+    "sha256": "57deb4aac01d98bc5af7bdfbaf6624367fa5f84595b2b5902acada824db53eab",
+    "consumer_tokens": [
+      "depth"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/check_monomial.py",
+    "sha256": "a301d39afb7475615716e2426c3df8fe0f6e8fa710c13f70ecb2a9026f52cd6d",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_parking.py",
+    "sha256": "7c84fa78dae732895ea016fcf3d1892f2519655dc5634b7e43a81b4ba7e187d8",
+    "consumer_tokens": [
+      "depth"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/check_prime.py",
+    "sha256": "791a0233fa704eafa634b6968c68f81a83b95170b30c527ba93599b8b8e76643",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_root.py",
+    "sha256": "7f7be44511d67aa4920cf7de4a88b3b78aab39cc210d20c06a456ee807f53614",
+    "consumer_tokens": [
+      "q0",
+      "depth",
+      "stock",
+      "padded_rows",
+      "original_rows"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/check_root_plan.py",
+    "sha256": "9f900532e6d564efd6af462f536f19301cb7674ab1b0670c0fc717ab63403da9",
+    "consumer_tokens": [
+      "q0",
+      "depth"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/check_root_streams.py",
+    "sha256": "46711e474f8cd4b20c99c8a790c416f055da64e293e2cf9a33db9e60294cc0ed",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_scalar.py",
+    "sha256": "23b3077ed0bb15c3f5f402d841fbf36845a00a63bbbc845f776c221050c943a4",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/check_selected.py",
+    "sha256": "3572fa98bbb0312e66fd15a7e0ed494db5c4f7b32087a8c87aeee2528b83daea",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/cohort.py",
+    "sha256": "8fb650c0cc3dfaad94811149b0c0e725777a8cff195c5f21e21a7576494e84f1",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/cover.py",
+    "sha256": "d797daec10275f439f6019c596b89afbc32a7716cb657648adfcaae2408949da",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/fixture_binding.py",
+    "sha256": "efcb94cf050412ccd2d5eea592d77f294f6124f6feebc86580b16a73e5c2c202",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/grid_boundary.py",
+    "sha256": "55f32b8cfaa3482d5d62127ac90c2370fc0dc8122263815e1564ee95093ffccc",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/machine.py",
+    "sha256": "b648792a361fdf98597a2f56c634767508be8e818b82e482fbfc60b5c63cc855",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/monomial_packets.py",
+    "sha256": "6856e80c13ebf3b6e9e0e142ed65420579b5a1b4892f23859d3c6e5f17a334b4",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/native_program.py",
+    "sha256": "177d87445659d7ddbef11370d0b4cdc0596732147ed26c1fa11bad16ae53c93b",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/parking.py",
+    "sha256": "33e6d2a6fcdc648de31b374132bf885259eec9748bafa6facca3822a78427e94",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/production_native.py",
+    "sha256": "4c1f8f69212162bd297010c6e21a32e31755cbfe2e40f9935b8d87a9e4260d46",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/root_layer.py",
+    "sha256": "247b82feefecedc12142379fd7c9c6cdd5ac7e5309e443c4b4fa703d6b995c21",
+    "consumer_tokens": [
+      "q0",
+      "padded_rows",
+      "original_rows"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/root_plan.py",
+    "sha256": "494cad3edc376928684f380cd16568076b286a53bd763d910d49efa5b03f07c9",
+    "consumer_tokens": [
+      "q0",
+      "depth",
+      "stock",
+      "padded_rows",
+      "original_rows"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/root_streams.py",
+    "sha256": "b67daf3de591b6788220a016b0394cfe2cc8e94ffd41426bb2544ad578b715c8",
+    "consumer_tokens": [
+      "padded_rows",
+      "original_rows"
+    ]
+  },
+  {
+    "path": "research/physical-complex-controller/scalar_packets.py",
+    "sha256": "cc48f726325c000ab2304eb691feb950ff4abeab5c537d6165d5b3322dc45c35",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/scalar_program.py",
+    "sha256": "4c005167b4c2fe0d98d2dd93b7f931b251259417ff4392b67ee0fbe290f6d48a",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/selected_binding.py",
+    "sha256": "d6583458d00e4933c3a3fd83cc376f21c059e9fc6aa338c00d66c1deeaa0e985",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/selected_source.py",
+    "sha256": "02601c9e7d88e58e62d63509ff709c6498a40fbbc0f95fab328379ae6acaa87a",
+    "consumer_tokens": []
+  },
+  {
+    "path": "research/physical-complex-controller/verify.py",
+    "sha256": "529f7a1e90b279f03ba4c8c5b0aeb98cd6935a50b95eb3475e9eada5cb5670cb",
+    "consumer_tokens": []
+  }
+]
diff --git a/research/minimum-root-row-prefix/PROOF.md b/research/minimum-root-row-prefix/PROOF.md
new file mode 100644
index 0000000000..fbb40eab49
--- /dev/null
+++ b/research/minimum-root-row-prefix/PROOF.md
@@ -0,0 +1,229 @@
+# Minimum row-reservation prefix at the actual root core
+
+This is a conditional root-interface theorem and an exact reference compiler.
+It concerns the original 73-dimensional physical backend retained by QQ16.
+It does not install a production Count frontend or prove a new kappa.
+
+## 1. Source contract and changed parameter
+
+The retained RootPlan has precision p>=2, global width
+`d=floor(p^(997/1000))`, spacing `K=floor(d^(1/500))`, selected width n<=d,
+`G=4 ceil(log2 p)+6`, and H=dG. Keep these fields and
+
+```text
+qF=ceil(2H/K),  qB=ceil(H/K),  M=n-qF-qB,
+F=14336 Gamma,  Gamma=2^1296 product_(j=1..36)(2^(2j)-1).
+```
+
+The selected-C backend has ranks {1,2,3,4,5,7,8,48}. It tests w<73 or
+w^1000<d before its remainder step. PR5515 supplies the exact depth
+
+```text
+T=max(73,ceil(d^(1/1000))),
+D(w)=0 for w<T; otherwise D(w)=1+D(48 floor(w/73)).
+```
+
+D is nondecreasing. All reached selected-C row divisions are positive and
+exact if and only if F^D(w) divides the incoming rows. This is inherited
+from PR5515; it is not a new depth theorem. Native/Ordinary internals retain
+the source's complete endpoint and admission contracts.
+
+The old plan uses `q0=2642 D0(d)`, where D0 ignores the height cutoff and
+2642=ceil(log2 F). It then creates **2^(K q0)** original rows. Thus q0 is
+an axis count, not a bit count. Every reserved axis already supplies K row
+bits. A shorter depth alone does not use this large difference.
+
+If M<=0, use the direct root leaf. Assume M>0 below. For a proposed integer
+q with 0<=q<M, the remaining core has width M-q. Define
+
+```text
+S(q)=F^D(M-q),       R(q)=2^(Kq),
+P(q)=ceil(R(q)/S(q)) S(q).
+```
+
+P is the padded row count. We retain the original strict volume promise
+`P(q)<2 R(q)`, complete prefixes, complete zero padding, and exact division
+by S(q). This is the format in which the minimum below is proved.
+
+## 2. Exact feasibility and minimum
+
+For positive integers S,R,
+
+```text
+ceil(R/S) S < 2R    if and only if    S < 2R.
+```
+
+If S>R, the left side is just S<2R. If S<=R, then
+`ceil(R/S) S < R+S <=2R`, including equality R=S in the second inequality.
+Thus the equivalence holds. For R=2^(Kq), it becomes
+
+```text
+floor(log2 S(q)) <= Kq.                                      (1)
+```
+
+This includes powers of two with the correct strict boundary. The source
+condition R>=S is sufficient but stronger: a stock between R and 2R also
+fits. The reference compiler uses `(S.bit_length()-1)`, with S=1 allowed.
+
+The left side of (1) is nonincreasing in q, and the right side is increasing.
+There is a unique least feasible q. The value q=M-1 is feasible because its
+core has width one and S=1. A smaller known upper bound is
+
+```text
+U=min(M-1, ceil(2642 D(M)/K)).
+```
+
+If the second branch applies, K U>=2642 D(M)>=log2 S(U). The first branch
+was already proved feasible. Binary search between the failed sentinel -1
+and U gives the exact minimum q*. Its certificate is the exact power-bit
+comparison at q* and the failed comparison at q*-1, unless q*=0.
+This proves the compiler for all inputs in the stated format; a finite
+width scan is not used as its proof.
+
+No smaller prefix in this same complete-row format can keep the strict
+factor-two volume bound. A different row encoding, a different permitted
+volume factor or a different supplier can have a different minimum.
+
+## 3. Bind the complete root interface
+
+Set the plan's q0=q*, depth=D(M-q*), and stock=S(q*). Recompute all dependent
+fields with the source formulas. Keep qF,qB and all global precision fields.
+The actual consumers are recorded in CONSUMER-INVENTORY.json. Both a lexical
+pass and an AST literal pass cover all 32 Python files in the retained
+physical-complex-controller directory. Tests are distinguished from production.
+The package pins all those files; it does not rely on their moving checkout.
+
+The production use chain is complete within this source module:
+
+1. RootPlan.compute derives Q0, original_rows, stock, padded_rows, core_width
+   and row_bits. No independent downstream depth consumer exists there.
+2. RootLayer.reserved_leaves uses q0+qF at the high selected end and qB at
+   the low end. These leave exactly M-q0 core axes.
+3. RootLayer.fast_core passes both row counts to RowPadding and passes
+   padded_rows as Machine's rows. It passes global d unchanged.
+4. RowPadding copies every genuine row under every prefix, appends zero
+   rows, and checks every removed padding bit on return. Machine divides
+   its incoming rows by F at each nonterminal selected-C node.
+
+The following identities hold for any admissible q0, not only the old choice:
+
+```text
+core_front=qF K-2H,     core_back=qB K-H+right,
+core_front+3H+(n-q0-qF-qB)K+core_back=(n-q0)K+right,
+prefixes=outer_rows*2^left,
+original_rows*2^((n-q0)K+right)=2^(nK+right).
+```
+
+Thus the root address partition and row serialization remain those proved
+by Jose Manuel and independently refined by Sagar Thakrar. There is no
+truncated high field, changed original payload or free private row. The
+three selected-axis regions are disjoint and cover all n axes. At the
+completed rowwise linear recursive endpoint, each added zero row is again
+zero, even if intermediate operations mix rows. The unchanged removal test
+therefore remains valid under that inherited endpoint premise.
+
+Since P is a positive multiple of F^depth, PR5515's exact-depth contract
+supplies every reached row quotient. Sequential children reuse it. No
+additional factor is lost at a sibling. Complete spectators stay in the
+source rectangle. This is a source-relative proof; it does not reprove the
+native, Ordinary, Compact or numerical endpoint.
+
+The compact guard also remains valid. Fast entry requires n>q0+qF+qB and
+n<=d, hence K>3G. The source's sufficient inequality
+`K>=3G+1>G+4 ceil(log2 p)+10` follows unchanged. Front/back residues lie in
+[0,K). The changed q0 is at most the old 2642D0(d). Its reserved-leaf count
+and descriptor extents therefore do not exceed that source allowance. The
+recursive core stays at most d; padded volume remains strictly below twice
+the original volume. The original exponent estimate can retain its former
+upper bounds. No improved total exponent follows from this finite reduction.
+
+For source inputs that were direct only because of the old q0, the new plan
+may choose a fast branch. The same guard and full endpoint argument apply;
+this does not grant a zero cost to the new core or the reserved leaves.
+
+## 4. One axis suffices eventually
+
+Fix the source divisor F. For every integer p>=2^14000 and every source
+selected width with M>0, the minimum is
+
+```text
+q*=0 if M<T; otherwise q*=1.                                (2)
+```
+
+Here is an explicit integer proof. Put u=floor(log2 p),
+`v=floor(997u/500000)`. Then K>=2^v and v>=27. Two maximum child steps
+contract by less than one half, since `2*48^2<73^2`. Hence
+
+```text
+D0(d)<=2 ceil(log2 d),
+2642 D0(d)<=5284(u+1).
+```
+
+For v>=27, `u+1 <= ceil(500000(v+1)/997)+1`. At v=27,
+
+```text
+2^27 = 134217728 > 74208496
+      = 5284(ceil(500000*28/997)+1).
+```
+
+Each increase in v raises the right side by at most 5284*502=2652568.
+The right side at 27 already exceeds this increment. Doubling the left
+side therefore preserves the strict inequality by induction. It follows
+that K>2642D0(d). For q=1 this is more than the required stock bit count
+at any core width at most d. If M>=T, q=0 has S>=F>1 and fails (1); q=1
+has a positive core and succeeds. If M<T, q=0 has S=1 and succeeds. This
+proves (2), with no floating logarithm and no unstated eventual constant.
+
+## 5. Exact source geometry at p=2^8500
+
+Use d=isqrt(2^16949), K=126519, T=356 and G=34006. The old coarse depth is
+13999 and its prefix is 36985358 axes.
+
+For n=d, the exact minimum is **293 axes**, with reached depth13993. The
+stock floor logarithm is36959276. The chosen row address has37070067 bits;
+292 axes have too few bits. Independent inverse thresholds from PR5515
+confirm the reached depth. No giant payload or row-count array is built.
+
+For the same selected input widths used by the old lambda45 and lambda72
+QQ16 band fixtures, the new minimum is **one axis**. The new cores have
+widths36988642 and36990613, both with depth28 and stock floor logarithm73955.
+This changes their internal core: the old one-generation C8 interpretation
+must not be carried over. These are root-plan witnesses, not a new matched
+QQ16 caller bill or the old call program with work silently removed.
+
+## 6. Construction cost and execution limits
+
+The reference compiler uses exact host integers. It is not a physical Count
+implementation. A direct encoded construction is as follows. Use the source
+fixed-degree integer-root routines to compute T. Store the endpoints and
+midpoint of the bounded binary search as Counts. For each candidate, subtract
+q from M, iterate the fixed maximum child map until below T, multiply a
+Count initially one by the fixed F once per level, scan its binary length,
+and compare that length minus one with Kq. Close each temporary before the
+next candidate. Save the final q and depth. Then use the existing source
+formulas to form stock, original_rows and padded_rows.
+
+With B=ceil(log2(p+2)) and fixed F, the depth is O(B), the search interval
+is O_F(B), and each trial stores O_F(B)-bit values. The T computation uses
+O(B) binary-search trials and fixed-degree integer products. A direct tape
+implementation can charge O_F(B^5) read/write/move actions and O_F(B^2)
+visited scratch bits, using scans for every indexed arithmetic access.
+These loose positive bounds include counters, copies, comparisons, returns
+and clearing. They require no random-access oracle or free host arithmetic.
+They are constructive planning bounds, not measurements of the retained
+Count routines. Integration must use actual Count primitives and meter it.
+
+The final original_rows descriptor can have O_F(B+K) bits: the known upper
+bound gives Kq*<=2642D0(d)+K. Its construction is separately charged by the
+source's output-bit scans; it is not hidden in the O(B)-bit trial workspace.
+The former bound was O_F(KB). All payload, parking, leaf and native costs
+remain paid. This package does not install a production frontend or execute
+production O73/GL64 payloads.
+
+The checker independently enumerates20000 minima using actual padded integer
+row counts, checks10245 all-child depth entries, and tests21 complete finite
+layout/tensor endpoints on dirty data. Those reduced layouts are declared
+address controls, not production p-geometries. Exact production descriptors
+and both sides of each claimed minimum are checked separately. The written
+proof supplies the all-parameter result. No proof-kernel or independent human
+acceptance is claimed.
diff --git a/research/minimum-root-row-prefix/README.md b/research/minimum-root-row-prefix/README.md
new file mode 100644
index 0000000000..a7c8e0f9ba
--- /dev/null
+++ b/research/minimum-root-row-prefix/README.md
@@ -0,0 +1,73 @@
+# Minimum root row prefix
+
+**An exact root-interface improvement; no new kappa.** The original QQ16
+physical backend reserves q0=ceil(log2 F)D0(d) selected axes, although each
+axis supplies K row bits. This package uses those bits and the depth of the
+actual remaining core. It proves the minimum prefix under the same strict
+factor-two padding budget and gives an exact reference compiler.
+
+At p=2^8500, the full selected width needs **293 reserved axes instead of
+36985358**. The reached depth is13993. At every p>=2^14000, **one axis**
+suffices for every nonterminal remaining core; a terminal core needs zero.
+These are source-relative row/geometry results. The complete paid supplier
+profile and selected multiplication exponent do not change.
+
+For remaining width M, the exact condition is
+
+```text
+floor(log2(F^D(M-q0))) <= K q0.
+```
+
+It is equivalent to the actual padded volume being strictly below twice the
+input volume. Binary search returns its least feasible q0. [PROOF.md](PROOF.md)
+proves the result and binds every retained source consumer of depth, q0 and
+stock. [RESULT.json](RESULT.json) gives exact evidence;
+[SOURCES.json](SOURCES.json) pins all sources.
+
+## Reproduce
+
+Python3.12 and the standard library suffice:
+
+```sh
+python3.12 -B scripts/research_package.py --package research/minimum-root-row-prefix
+python3.12 -I -O -B research/minimum-root-row-prefix/verify.py
+```
+
+Expect `PASS_MINIMUM_ROOT_ROW_PREFIX` and the registered package pass. The
+checks include20000 direct padded-volume minima,10245 full-child depth
+entries,21 complete finite dirty-data endpoints, production geometry at
+p=2^8500, a separate inverse-depth oracle, and the one-axis tail certificate.
+All32 Python files in the source controller are covered by the consumer
+inventory. The code authenticates40 source inputs before checks.
+
+The integer compiler is a reference implementation. The proof gives a paid
+encoded algorithm and preserves the source row/guard/padding contracts; it
+does not claim installed physical Count execution. The finite layout tests
+use exact tensor endpoints on reduced address controls. Native correctness,
+physical primitive admission, production payloads and the matched QQ16
+comparison remain separate. [VALIDATION.md](VALIDATION.md) records replay
+and publication checks.
+
+## Open next questions
+
+Implement the specified encoded planner at the RootPlan injection boundary,
+retain all output fields, and execute reduced complete roots with source
+Count/record primitives. Meter setup and every added operation. Production
+geometry remains too large for a payload fixture. If the QQ16 intervention
+is then reused, bind its changed core and all later calls again; the old
+lambda45/72 internal band does not survive this replanning automatically.
+
+## Credit
+
+commdata2338's [PR5515](https://github.com/CrocSwap/integer-mult-bounds/pull/5515)
+supplies exact reached depth, its inverse thresholds and the root-stock
+handoff. Nick Petalas's PR4865 supplies the parking recurrence lineage.
+Jose Manuel's PR3385 supplies the RootPlan and full source controller.
+Sagar Thakrar's complex-root-address-refinement supplies the general address
+and zero-padding argument, already present in the source proof. Their byte
+copies and notices remain in vendor/. This work supplies the exact optimal
+prefix, the eventual one-axis theorem, source-consumer binding and new checks.
+Prepared by Ali Romman with substantial OpenAI Codex assistance. No subagents.
+Apache-2.0. No human or formal-kernel review is claimed. Base main
+ df0137efd35e11b4445734bf612bdd4c7ebc330c, priority7.
+[Canonical claim](https://github.com/CrocSwap/integer-mult-bounds/discussions/4744#discussioncomment-19188925).
diff --git a/research/minimum-root-row-prefix/RESULT.json b/research/minimum-root-row-prefix/RESULT.json
new file mode 100644
index 0000000000..ebf1786045
--- /dev/null
+++ b/research/minimum-root-row-prefix/RESULT.json
@@ -0,0 +1,90 @@
+{
+  "authenticated_inputs": 40,
+  "consumer_audit": {
+    "bound_plan_formulas": 8,
+    "production_literal_consumers": {
+      "root_layer.py": [
+        "original_rows",
+        "padded_rows",
+        "q0"
+      ],
+      "root_plan.py": [
+        "depth",
+        "original_rows",
+        "padded_rows",
+        "q0",
+        "stock"
+      ]
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new file mode 100644
index 0000000000..34dfaeac78
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diff --git a/research/minimum-root-row-prefix/TASK.json b/research/minimum-root-row-prefix/TASK.json
new file mode 100644
index 0000000000..69760a0e70
--- /dev/null
+++ b/research/minimum-root-row-prefix/TASK.json
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+{
+  "schema_version": 1,
+  "task_id": "joint-query-controller",
+  "priority_revision": 7,
+  "base_commit": "df0137efd35e11b4445734bf612bdd4c7ebc330c",
+  "original_card": {
+    "id": "joint-query-controller",
+    "question": "Can the installed QQ16 caller win a complete matched protocol bill, or can a changed demand eliminate actual paid work?",
+    "starting_points": [
+      "docs/research/research-family-status.md",
+      "certificates/selected-result.json",
+      "research/qq16-caller-install/README.md"
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+    "methods": [
+      "Derive the matched whole-caller physical bill for installed and baseline protocols.",
+      "Change the actual demanded observations and prove a cheaper legal producer/consumer contract."
+    ],
+    "acceptance_gate": "Name the changed premise of the fixed F0/B1 observation obstruction. Show exactly which query is recovered, legal native reads and restoration, and a full favorable budget including cover maps, helpers and endpoints. Local inverse identities alone do not close the global controller. A scoped local result may be retained without a complete supplier. Expanding it into further construction rounds requires the family-level budget and obligation gate in research-family-status.md; an optimistic passing relaxation alone is not acceptance.",
+    "first_step": {
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+      ],
+      "expected": "PASS_RESEARCH_BASELINE_BINDINGS_ONLY",
+      "inspect": "Read #4166 COST.md and ADMISSION.json. An actual caller connection is now proposed. Its native-component profile loses; parent park/restore versus external-call costs remain unresolved. Retain the producer and recovery lineage rather than rebuild it.",
+      "scope": "Source-binding orientation only; no scientific replay, theorem acceptance or supplier admission. Budget any heavy replay separately."
+    },
+    "first_experiment": "At the actual installed cut, compare matched complete parent park/restore and external input/return protocols at the same bank/packet geometry, including every later root call and service cost. Alternatively pin both bridge observations and derive a genuinely smaller source-compatible demand. Stop if the complete necessary inequality fails or an essential cost is unknown; no larger decoder scan from a local tape-action saving.",
+    "bottleneck_link": "The native local words exist; retained query information and its physical access are the missing link to a composed recursive interface.",
+    "allowed_variations": [
+      "One paid query, one changed first pair, or one precisely specified affine helper state.",
+      "A counterexample or lower bound for that exact proposed repair.",
+      "One unresolved obligation of a newer local decoder, with exact source heads and a distinct claim/domain."
+    ],
+    "scope_change_triggers": [
+      "Retaining the fixed first pair and ordinary schedule while allowing only homogeneous selected-only control, already excluded by the witness.",
+      "Treating cover-map counts as zero-cost physical address operations.",
+      "Recreating the pending complete local decoder or early-record/output-bank coalescing already under investigation without a distinct audit or changed premise.",
+      "Treating a completed-output defect inequality as a producer-interior, dirty-range or physical-cost certificate.",
+      "Recreating completed-output recovery or caller wiring already supplied by #4166 without new independent coverage.",
+      "Dropping retained later root calls or claiming native-profile dominance from the isolated publication saving."
+    ],
+    "overlap_terms": [
+      "QQ16",
+      "joint-query",
+      "changing-chart controller",
+      "selected observation",
+      "1969",
+      "2540",
+      "early record",
+      "output-bank retention",
+      "complete native decoder",
+      "2965",
+      "producer defect",
+      "dirty-helper range",
+      "F17 consumer",
+      "4166",
+      "qq16-caller-install"
+    ],
+    "existing_checks": [
+      {
+        "scope": "PR #4166: author-checked installed producer/service/return/bridge connection; native-component comparison loses.",
+        "evidence": "research/qq16-caller-install/README.md",
+        "remaining": "Complete matched physical protocol bill, or changed source-compatible demand/circuit; no affordable supplier yet.",
+        "status": "author-checked",
+        "source_commit": "0b082d22a0e9a442d264ab0633e35ef26c790630",
+        "selected_record_sha256": "bb2eaa58647b353f88d0aec2eafb9d30df1be53589231b23e12ceef3e4bad129"
+      }
+    ]
+  },
+  "scope_status": "refined",
+  "actual_scope": "Minimum root row-prefix under the actual strict factor-two padding budget, with self-consistent reached depth and a one-axis eventual theorem.",
+  "scope_change_reason": "Explicit released PR5515 RootPlan handoff; use actual K-bit row axes rather than only shorten the depth.",
+  "bottleneck_link": "Reduce the reserved direct-leaf prefix and its row descriptors while preserving the complete recursive row/stock interface.",
+  "budget_minutes": 120,
+  "stop_rule": "Prove the exact optimum in this format and bind all source consumers. Do not claim a matched QQ16 price or a frontier change.",
+  "outcome": "completed",
+  "evidence": "PROOF.md and RESULT.json; integer reference compiler, exact source and finite layout checks.",
+  "author": "Ali Romman with substantial OpenAI Codex assistance",
+  "ai_assistance": "OpenAI Codex; no subagents. No human or formal-kernel review.",
+  "open_questions": [
+    {
+      "question": "Can the encoded planner be installed in an actual RootPlan and full caller?",
+      "why_it_matters": "The proof supplies an admissible optimal prefix, but production payload and Count execution are separate.",
+      "first_step": "Implement the stated Count algorithm and use the source plan injection boundary; meter setup and run reduced complete roots.",
+      "blocked_by": "Complete physical source closure and production geometry are not replayed here."
+    }
+  ],
+  "coordination": {
+    "claim": "https://github.com/CrocSwap/integer-mult-bounds/discussions/4744#discussioncomment-19188925",
+    "picker_nonce": "cd3d4419157af0152089cec7e5300475",
+    "main": "df0137efd35e11b4445734bf612bdd4c7ebc330c",
+    "priority_revision": 7
+  }
+}
diff --git a/research/minimum-root-row-prefix/VALIDATION.md b/research/minimum-root-row-prefix/VALIDATION.md
new file mode 100644
index 0000000000..a7c6685fde
--- /dev/null
+++ b/research/minimum-root-row-prefix/VALIDATION.md
@@ -0,0 +1,31 @@
+# Verification record
+
+CPython3.12.14 normal and optimized registered runs reproduce RESULT.json.
+The direct exact-integer run also passes on Python3.14.7. The source audit
+pins all32 Python files in the retained controller; eight copied source
+files include the proof and actual consumer code. No source is edited.
+
+The numerical oracle for20000 minima constructs the actual small padded row
+counts, independently of the bit-length feasibility test. The10245 depth
+entries use all child ranks. The21 finite tensor/layout fixtures use dirty
+integer data and a nontrivial nonsymmetric two-by-two linear map. They are
+layout controls, not physical Count/native execution. Nonzero returned
+padding is rejected. Production core depths also pass an independent inverse
+threshold calculation. Both sides of every claimed production minimum use
+exact stock powers. The one-axis theorem has an explicit integer induction.
+
+The science commit d681ccd1ab1599481c84a3b3fcacb869612ca8c1 passed the
+50-file committed-byte and official archive checks. Optimized isolated
+replay passed with empty PATH in a read-only Git-free export. All51 files,
+including the manifest, kept their hashes. An appended source line in the
+actual retained root_layer.py caused rejection before science checks.
+A separate Git-tree inventory agrees with all32 controller Python paths.
+The final documentation commit leaves the science bytes unchanged and passes
+a final committed-byte check and export. The fresh overlap cache covers372
+open PRs and5001 Discussion records, with complete pagination, plus all
+tracked main notes. Canonical main remains df0137efd35e11b4445734bf612bdd4c7ebc330c.
+Unpublished work and arbitrary diffs remain outside overlap coverage. No
+production payload, physical Count integration, full native/ordinary/outer
+replay, selected cold replay, human review or proof-kernel check is claimed.
+The shallow checkout has no full-history preflight. Exact base/input bytes
+and immediate retained-source ancestry are checked. Hosted CI is separate.
diff --git a/research/minimum-root-row-prefix/VERIFY.json b/research/minimum-root-row-prefix/VERIFY.json
new file mode 100644
index 0000000000..51c33c5648
--- /dev/null
+++ b/research/minimum-root-row-prefix/VERIFY.json
@@ -0,0 +1,59 @@
+{
+  "schema_version": 1,
+  "status": "ready",
+  "python": "3.12",
+  "requirements": [],
+  "inputs": [
+    "research/minimum-root-row-prefix/vendor/ADDRESS-PROOF.md",
+    "research/minimum-root-row-prefix/vendor/PR5515-PROOF.md",
+    "research/minimum-root-row-prefix/vendor/PR5515-README.md",
+    "research/minimum-root-row-prefix/vendor/ROOT-PROOF.md",
+    "research/minimum-root-row-prefix/vendor/machine.py",
+    "research/minimum-root-row-prefix/vendor/root_layer.py",
+    "research/minimum-root-row-prefix/vendor/root_plan.py",
+    "research/minimum-root-row-prefix/vendor/root_streams.py",
+    "research/physical-complex-controller/bank_packets.py",
+    "research/physical-complex-controller/check_bank.py",
+    "research/physical-complex-controller/check_bounds.py",
+    "research/physical-complex-controller/check_cover.py",
+    "research/physical-complex-controller/check_failures.py",
+    "research/physical-complex-controller/check_grid.py",
+    "research/physical-complex-controller/check_machine.py",
+    "research/physical-complex-controller/check_monomial.py",
+    "research/physical-complex-controller/check_parking.py",
+    "research/physical-complex-controller/check_prime.py",
+    "research/physical-complex-controller/check_root.py",
+    "research/physical-complex-controller/check_root_plan.py",
+    "research/physical-complex-controller/check_root_streams.py",
+    "research/physical-complex-controller/check_scalar.py",
+    "research/physical-complex-controller/check_selected.py",
+    "research/physical-complex-controller/cohort.py",
+    "research/physical-complex-controller/cover.py",
+    "research/physical-complex-controller/fixture_binding.py",
+    "research/physical-complex-controller/grid_boundary.py",
+    "research/physical-complex-controller/machine.py",
+    "research/physical-complex-controller/monomial_packets.py",
+    "research/physical-complex-controller/native_program.py",
+    "research/physical-complex-controller/parking.py",
+    "research/physical-complex-controller/production_native.py",
+    "research/physical-complex-controller/root_layer.py",
+    "research/physical-complex-controller/root_plan.py",
+    "research/physical-complex-controller/root_streams.py",
+    "research/physical-complex-controller/scalar_packets.py",
+    "research/physical-complex-controller/scalar_program.py",
+    "research/physical-complex-controller/selected_binding.py",
+    "research/physical-complex-controller/selected_source.py",
+    "research/physical-complex-controller/verify.py"
+  ],
+  "commands": [
+    {
+      "argv": [
+        "{python}",
+        "-B",
+        "{package}/verify.py"
+      ],
+      "timeout_seconds": 180,
+      "checks": "Exact minimum, complete finite dirty-row endpoints, full source-consumer audit, production geometry and one-axis tail certificate."
+    }
+  ]
+}
diff --git a/research/minimum-root-row-prefix/reserve.py b/research/minimum-root-row-prefix/reserve.py
new file mode 100644
index 0000000000..5d3bd76fb7
--- /dev/null
+++ b/research/minimum-root-row-prefix/reserve.py
@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+"""Exact reference compiler for the root row prefix.
+
+This uses host integers. It does not execute physical Count or payload code.
+Ali Romman with substantial OpenAI Codex assistance. Apache-2.0.
+"""
+from functools import lru_cache
+
+
+def need(ok, message):
+    if not ok:
+        raise ValueError(message)
+
+
+def floor_root(n, degree):
+    need(type(n) is int and n >= 0 and type(degree) is int and degree > 0, 'root domain')
+    lo, hi = 0, 1 << ((n.bit_length()+degree-1)//degree)
+    while lo+1 < hi:
+        mid = (lo+hi)//2
+        if mid**degree <= n:
+            lo = mid
+        else:
+            hi = mid
+    return hi if hi**degree <= n else lo
+
+
+def depth(width, threshold, dimension=73, maximum_rank=48):
+    need(type(width) is int and width >= 0, 'nonnegative width')
+    need(type(threshold) is int and threshold >= dimension > maximum_rank > 0, 'depth domain')
+    result = 0
+    while width >= threshold:
+        width = maximum_rank*(width//dimension)
+        result += 1
+    return result
+
+
+class PrefixCompiler:
+    def __init__(self, divisor, threshold, dimension=73, maximum_rank=48):
+        need(type(divisor) is int and divisor > 1, 'positive nontrivial divisor')
+        need(threshold >= dimension > maximum_rank > 0, 'compiler domain')
+        self.divisor = divisor
+        self.threshold = threshold
+        self.dimension = dimension
+        self.maximum_rank = maximum_rank
+
+    def active_depth(self, width):
+        return depth(width, self.threshold, self.dimension, self.maximum_rank)
+
+    @lru_cache(maxsize=256)
+    def stock_bits(self, levels):
+        return (self.divisor**levels).bit_length()-1
+
+    def feasible(self, remaining, spacing, prefix):
+        need(0 <= prefix < remaining and spacing >= 1, 'positive core')
+        levels = self.active_depth(remaining-prefix)
+        return self.stock_bits(levels) <= spacing*prefix
+
+    def compile(self, remaining, spacing):
+        need(type(remaining) is int and remaining >= 1 and type(spacing) is int and spacing >= 1, 'prefix domain')
+        # This known feasible upper bound avoids a search through the root width.
+        conservative = self.active_depth(remaining)*(self.divisor-1).bit_length()
+        upper = min(remaining-1, (conservative+spacing-1)//spacing)
+        lower = -1
+        while upper-lower > 1:
+            middle = (lower+upper)//2
+            if self.feasible(remaining,spacing,middle):
+                upper = middle
+            else:
+                lower = middle
+        levels = self.active_depth(remaining-upper)
+        need(self.feasible(remaining,spacing,upper), 'feasible minimum')
+        need(upper == 0 or not self.feasible(remaining,spacing,upper-1), 'strict minimality')
+        return {'q0':upper, 'depth':levels, 'stock_floor_log2':self.stock_bits(levels),
+                'row_address_bits':spacing*upper,
+                'previous_stock_floor_log2':None if upper==0 else self.stock_bits(self.active_depth(remaining-upper+1))}
diff --git a/research/minimum-root-row-prefix/vendor/ADDRESS-PROOF.md b/research/minimum-root-row-prefix/vendor/ADDRESS-PROOF.md
new file mode 100644
index 0000000000..158cd78492
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/ADDRESS-PROOF.md
@@ -0,0 +1,264 @@
+# The original root's reserved axes and padded core rectangle
+
+Copyright 2026 Sagar Thakrar. Apache-2.0.
+Prepared with substantial OpenAI Codex assistance.
+
+This is a conditional address refinement of `reserved_leaves` and `fast_core`
+in Jose Manuel's original PR3385 `root_layer.py`, at
+`7e5a187214126d31afc241a8f89f4a652352b58c`. It explains how the three source
+calls cover exactly the selected tensor axes and why the temporary row
+padding can be removed. It does not independently prove the recursive
+machine, its numerical precision, the normalized root, or its cost bound.
+The source and its predecessors already claim the tensor decomposition;
+the contribution here is an independent derivation at these literal
+descriptor and serialization boundaries.
+
+## 1. Domain and endpoint contracts
+
+Let $D,q_0,q_F,q_B,H,l,r$ be nonnegative integers, and let $K,O,F,w$
+be positive integers. Here $l,r$ are the left and right spectator widths,
+$O$ is the outer-row count, $F$ is the number of Gaussian coefficients per
+address, and $w$ is a signed component width. Let $0\le\rho<K$ and put
+
+\[
+ a=q_0+q_F,\qquad c=D-a-q_B>0,
+ \qquad f=q_FK-2H\ge0,\qquad b=q_BK-H+r\ge0.
+\]
+
+The fast branch has the strict inequality $D>Q_0=q_0+q_F+q_B$.
+The two nonnegative-width conditions hold for the production choices
+$q_F=\lceil2H/K\rceil$ and $q_B=\lceil H/K\rceil$.
+
+Within each outer row the payload is ordered by increasing binary address
+of width $l+DK+r$. Within each address the $F$ Gaussian coefficients occur
+in order, each with a real and imaginary component of width $w$.
+Address bit positions are counted from the least significant bit. The
+selected positions are
+
+\[
+ S=\{r+\rho+jK:0\le j<D\}.
+\]
+
+The other address bits are spectators. Component-bit order is irrelevant
+to the address argument, provided all callees preserve the same component
+serialization. No conversion between inner and outer coefficient formats
+is asserted here.
+
+We retain the following contracts explicitly.
+
+1. An exact leaf with widths `(left, selected*K, right)` applies its
+   declared tensor factor $C$ on positions `right+rho+j*K`, independently
+   for every outer row and coefficient, and is the identity on every other
+   address factor at its completed endpoint. It preserves the complete
+   rectangle and returns in the source's required tape state. This remains
+   true for arbitrary correlations among the fields.
+2. The completed recursive machine with the supplied descriptors applies
+   $C^{\otimes c}$ on its active spaced positions independently for each
+   prefix, row, coefficient and choice of spectator bits. It restores the
+   entire rectangle, including the three compact fields, at its endpoint.
+   Its implementation may temporarily move or mix rows or use compact
+   fields; the completed endpoint must have this rowwise action.
+3. These operators are linear, hence send a zero row to a zero row.
+   Numerical headroom, exact divisions, physical ownership, source/target
+   separation and closed scratch needed to realize their endpoints are
+   inherited contracts. This address proof supplies none of those bounds.
+4. The plan fields denote the integers specified here, the input packet is
+   complete, and the unchanged transfer and encoded-count routines realize
+   their declared copy/move and arithmetic operations. Count cursor and
+   tape cleanup guarantees are retained with those physical routines.
+
+The conclusion below is an implication from these contracts. A finite
+coordinate-routing witness is not a substitute for them.
+
+## 2. The two reserved leaves
+
+The source first computes `prefix=q0+qF`, `tail=selected-prefix`, and
+`suffix=tail*K+right`. Its first `apply_leaf` call therefore has widths
+
+\[
+ (l,\ aK,\ (D-a)K+r).
+\]
+
+By the leaf contract it acts on positions
+
+\[
+ r+(D-a)K+\rho+tK,\qquad 0\le t<a.
+\]
+
+These are exactly the original selected indices $j=D-a,\ldots,D-1$.
+The widths sum to $l+DK+r$; no spectator or component is discarded.
+
+The source next computes `left=(selected-qB)*K+left` and calls the leaf
+with widths
+
+\[
+ (l+(D-q_B)K,\ q_BK,\ r).
+\]
+
+This acts exactly on original selected indices $j=0,\ldots,q_B-1$.
+If either reserved width is zero, the source's zero-width return implements
+the empty tensor product. Both leaves operate separately on all $O$ outer
+rows and all $F$ coefficients. They may create correlations between the
+eventual row labels and other fields; no product-state assumption is used.
+
+## 3. Reinterpreting the complete packet as rows
+
+After the reserved leaves, divide each address into the following fields,
+written from most significant to least significant:
+
+\[
+ [\text{left}:l]\ [\text{row}:q_0K]\
+ [\text{front reserve}:q_FK]\ [\text{core}:cK]\
+ [\text{back reserve}:q_BK]\ [\text{right}:r].
+\]
+
+This is a reinterpretation of the existing serialization, not a movement
+of selected coordinates. The original outer-row index together with the
+left field gives
+
+\[
+ P=O2^l\quad\text{prefixes},\qquad R=2^{q_0K}\quad\text{rows per prefix}.
+\]
+
+Each row has $A=(D-q_0)K+r$ address bits and
+
+\[
+ B=2^A\,F\,(2w)
+\]
+
+serialized component bits. These are exactly the source's `prefixes`,
+`original_rows`, and `row_bits`. The identity
+
+\[
+ PRB=O\,2^{l+DK+r}\,F\,(2w)
+\]
+
+accounts for the entire packet, including all spectators and coefficients.
+
+For any positive stock $T$, set $R'=T\lceil R/T\rceil$. The source's
+`RowPadding.run` consumes $RB$ bits for each of the $P$ prefixes and then
+appends $(R'-R)B$ zeros. Consequently the old coordinate
+$(p,u,x,k)$, where $0\le u<R$, is retained as $(p,u,x,k)$ in the padded
+rectangle; $k$ denotes the within-address coefficient/component bit.
+The only change to a serialized offset is the larger stride between
+prefixes. Rows $R\le u<R'$ are complete zero rows. Appending one zero block
+only at the end of the whole packet would not have this property when
+$P>1$; the source loops over prefixes.
+
+## 4. The recursive descriptor selects the middle axes
+
+The source passes `before=after=0`, `width=c`, `spacing=K`, `residue=rho`,
+`compact_bits=H`, `front=f`, and `back=b` to the recursive machine. Its
+row geometry is therefore
+
+\[
+ [f]\ [H]\ [H]\ [cK]\ [H]\ [b].
+\]
+
+The source identifies this with the preceding rectangle because
+
+\[
+ f+2H=q_FK,\qquad H+b=q_BK+r,
+\]
+
+and hence
+
+\[
+ f+3H+cK+b=(D-q_0)K+r=A.
+\]
+
+Thus its selected position $t$ is
+
+\[
+ b+H+\rho+tK=r+\rho+(q_B+t)K,\qquad0\le t<c.
+\]
+
+The recursive call acts exactly on original selected indices
+$j=q_B,\ldots,D-a-1$. It preserves the other bits by the retained endpoint
+contract, including compact-field bits on which an earlier reserved leaf
+may already have acted. The row and prefix descriptors are respectively
+$R'$ and $P$; `component_bits`, `coefficients`, `guard`, and `root_width`
+are passed from the plan without changing their meanings.
+
+## 5. Unpadding and the tensor implication
+
+By the rowwise homogeneous recursive endpoint, an appended zero row is
+still zero when the recursive call returns. `RowPadding.run(remove=True)`
+copies each original $RB$-bit block and checks every bit in that prefix's
+appended block is zero before skipping it. It therefore restores the
+original $P\times R$ rectangle exactly. A nonzero appended bit is rejected;
+this is an explicit check, not silent truncation. The zero claim relies
+on the completed endpoint, not on intermediate rows staying zero.
+
+The three selected-index intervals are pairwise disjoint and satisfy
+
+\[
+ \{0,\ldots,q_B-1\}\ \dot\cup\
+ \{q_B,\ldots,D-a-1\}\ \dot\cup\
+ \{D-a,\ldots,D-1\}=\{0,\ldots,D-1\}.
+\]
+
+Operators on these distinct tensor factors commute. Therefore the source's
+chronological sequence of first reserved leaf, second reserved leaf and
+padded recursive core has endpoint $C^{\otimes D}$ on exactly $S$, with
+the identity on all remaining address factors and with every coefficient
+and outer row retained. This is the middle unnormalized transform only.
+It does not prove the surrounding phase sweeps, multiplication by $((1-i)/2)^D$,
+signed truncation, the unit-disk/error conclusion, or the full root theorem.
+
+## 6. Production stock and the padding factor
+
+For the source's fixed level divisor $L>1$ and coarse depth $h\ge0$, the
+plan sets
+
+\[
+ q_0=h\lceil\log_2 L\rceil,\qquad T=L^h.
+\]
+
+Since $K\ge1$, $R=2^{q_0K}\ge L^h=T$. For positive $R,T$,
+
+\[
+ R\le R'=T\lceil R/T\rceil<R+T\le2R.
+\]
+
+This proves the strict less-than-two volume enlargement at this padding
+boundary, with all other fields unchanged. The depth-zero case has
+$q_0=0$, $R=T=R'=1$. This does not prove the child stock induction,
+descriptor setup cost, or the global running-time invoice.
+
+The address theorem itself only needs $R'\ge R$ and complete row padding;
+the stock law is an additional premise for the factor bound and production
+admission. Reduced fixtures with injected plan fields are labelled as such
+and do not establish the production parameter law.
+
+## 7. Evidence, prior coverage and attribution
+
+The original `check_root.py` tests a complete reduced fast root with
+$K=1$, $\rho=0$, zero left/right spectators, one coefficient and one outer
+row. Its original and padded row counts are both eight. The original
+`check_root_streams.py` separately checks a phase sweep at $K=2,\rho=1$
+and prefix padding with unequal row counts. These are useful prior checks;
+they do not jointly exercise the nontrivial fast-root descriptor boundary.
+
+The finite checks in this package use explicitly declared routing endpoints
+to inspect literal call descriptors and complete packet coordinates, with
+real source padding and transfer routines. Such a routing endpoint is not
+the numerical operator $C$. Its role is to distinguish address mistakes
+and expose padding or spectator loss. The universal tensor conclusion is
+the conditional argument above, not an inference from those finite maps.
+
+Jose Manuel (`jmbarrancoml`) supplied PR3385's root, planner, physical
+cohort and credited PR2287 construction, retaining the numerical, native,
+hosting, ordinary-backend and normalization lineage. His later T74 layer
+retains the reduced fast fixture; no T74 production execution is claimed
+here. Nick Petalas's `t74-outer-format-plan` already supplies the outer
+dimension and signed component-order adapter and reduced direct-root tests
+with nonzero spectators and multiple coefficients/rows. Its proof explicitly
+retains root correctness. This package does not reclaim that adapter or a
+new tensor identity. Exact predecessor pins and original notices are in
+the accompanying source manifest.
+
+This is a written source-relative implication with finite layout controls,
+not a proof-assistant certificate, complete source-to-machine refinement,
+fixed-prime factory admission, outer multiplication theorem, or a change
+to the selected frontier.
diff --git a/research/minimum-root-row-prefix/vendor/PR5515-PROOF.md b/research/minimum-root-row-prefix/vendor/PR5515-PROOF.md
new file mode 100644
index 0000000000..fa69dec13a
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/PR5515-PROOF.md
@@ -0,0 +1,262 @@
+# A global-root cutoff in the QQ16 parking recurrence
+
+## Domain and inherited premises
+
+Fix the historical original selected-C backend retained by QQ16 #4166,
+as identified in [#4753](../qq16-nonterminal-c8-tree/README.md). Its dimension
+is 73. Write **d for the positive integer global root-width descriptor**;
+this is not the fixed dimension. At each selected-C node of integer width w,
+the source tests `w < 73 or w**1000 < d` before stripping a remainder.
+Only widths `0 <= w <= d` have a source interpretation. The recurrence below
+also makes sense outside that range, without claiming source admission.
+
+The inherited histogram and full-bank relation are
+
+| r | 1 | 2 | 3 | 4 | 5 | 7 | 8 | 48 |
+| --- | ---: | ---: | ---: | ---: | ---: | ---: | ---: | ---: |
+| n_r | 349604 | 60192 | 62585 | 20448 | 11808 | 7 | 1152 | 4866 |
+
+Put `N = sum n_r = 510662`, `F = 14336 Gamma`, `c_r = n_r/14336`, and
+`C = sum c_r = 255331/7168`. Gamma is the same positive integer owner
+multiplier throughout this fixed backend. A nonterminal node has `n_r Gamma`
+children of width `r floor(w/73)`. Each child's incoming rows and complete
+bank volume are the parent's divided by F. Calls are sequential; their row
+quotients are reused, not consumed additively. These are cited source premises,
+not a new full literal-word census or physical correctness proof.
+
+The only priced subtrace is one current-bank volume per selected-child
+park/restore pair. Ordinary/native internals, remainder leaves, other parked
+roles, restore actions and candidate work are outside that quantity. In
+particular the source-action floor `(2,5,5)` per parked bank bit is inherited
+from #4753, not a complete park/restore invoice proved here.
+
+## Exact cutoff and recurrence
+
+For every integer d >= 1 define
+
+\[
+T_d=\max(73,\lceil d^{1/1000}\rceil),\qquad
+H_d(w)=\begin{cases}
+0,&w<T_d,\\
+1+\sum_r c_r H_d(r\lfloor w/73\rfloor),&w\ge T_d.
+\end{cases}
+\]
+
+For integer w, `w**1000 < d` is equivalent to
+`w < ceil(d**(1/1000))`, including when d is a perfect 1000th power.
+The strict inequality matters at equality. If w=73q+delta is nonterminal,
+the source reaches its selected program at 73q without repeating the test.
+Thus the recurrence tests the original w, and recurses on rq. Every edge
+contracts by at most rho=48/73, so the recurrence is well defined.
+
+The actual `Machine.node` computes columns=q and unused rows=R/F.
+The actual `prepare_child` sets width=rq, rows=R/F, and
+`after'=after+(73-r)q*spacing`; it forwards root_width unchanged. The preceding
+remainder step replaces `before` by `before+delta*spacing`. Hence
+
+\[
+b=3\,\mathrm{compact\_bits}+\mathrm{front}+\mathrm{before}
+  +w\,\mathrm{spacing}+\mathrm{after}+\mathrm{back}
+\]
+
+is preserved by both steps. All prefix/component/coefficient descriptors are
+also preserved. Consequently the bank volume, including spectators, is
+divided by F, not by a width ratio. These source statements explain the
+recurrence's weights. `source_probe.py` executes these two unchanged methods
+over an exact descriptor-integer interpreter; it does not execute records,
+native payloads, Count arithmetic algorithms or their costs.
+
+If the incoming bank has complete volume v, summing current-bank volume over
+all selected-child parking pairs gives
+
+\[
+P_d(w,v)=N\Gamma v H_d(w).
+\]
+
+Indeed a depth-j rank path has multiplicity
+`Gamma**j product(n_r)` and volume `v/F**j`. Their Gamma factors cancel
+inside the path weight, but the `N Gamma` child invocations at that node
+remain. For sixteen removed C8 calls per outer cover, the corresponding
+quantity is `16 N Gamma**2 v H_d(8 lambda)`, when `8 lambda <= d` and all
+other source premises hold. It is already part of the removed complete C8
+bodies; it cannot be added a second time to a matched invoice.
+
+## Uniform envelope
+
+Let s be the unique number in (0,1) satisfying
+
+\[
+M(s)=\sum_r c_r(r/73)^s=1.
+\]
+
+Existence and uniqueness follow from strict decrease and
+`M(0)=255331/7168 > 1`, `M(1)=1041408/1046528 < 1`.
+This is exactly #4865's existing exponent, not a new root search. Its
+published bracket is `0.9983245373 < s < 0.9983245374`; the present proof
+needs only the defining equation and `0<s<1`.
+
+Set `a = 3456/25` and `q_T = floor(T_d/73) >= 1`. For every w >= T_d,
+
+\[
+\boxed{\quad
+\frac{((w+a)/(T_d-1+a))^s-1}{C-1}
+\le H_d(w)\le
+\frac{(w/q_T)^s-1}{C-1}.
+\quad}
+\]
+
+The proof uses Nick Petalas's #4865 weighted-leaf argument with the cutoff
+kept as a parameter. To make the extension's dependence explicit, let L be
+the total terminal-leaf weight in the finite rank tree. Replacing one
+frontier vertex by its children multiplies that vertex's weight by C.
+Telescoping gives `L=1+(C-1)H_d(w)`. Every terminal leaf below a nonterminal
+root has width in `[floor(T_d/73), T_d-1]`.
+
+For phi(x)=x^s, at an internal width w=73q+delta,
+`sum c_r phi(rq)=(73q)^s <= phi(w)`. Telescoping implies
+`q_T^s L <= w^s`, giving the upper bound. For psi(x)=(x+a)^s,
+
+\[
+a\ge\max_{r,0\le\delta\le72}\frac{r\delta}{73-r}
+ =\frac{48\cdot72}{25},\qquad
+rq+a\ge(r/73)(w+a).
+\]
+
+Thus `sum c_r psi(rq) >= psi(w)`. Terminal widths are at most T_d-1,
+so `(T_d-1+a)^s L >= (w+a)^s`, giving the lower bound. The potential
+functions and sharp per-edge affine shift are predecessor work; retaining
+the moving cutoff and applying the result to changing d is the new scope.
+
+The constants can also be made uniform simultaneously in both parameters.
+Put `A=1+a/73=5281/1825` and `X=(w/T_d)^s`. Since
+`T_d-1+a <= A*T_d` and `floor(T_d/73) >= T_d/146`, the envelope and H>=1 give
+
+\[
+\frac{X}{C A^s}\le H_d(w)\le\frac{146^s}{C-1}X
+\quad (w\ge T_d).
+\]
+
+For the lower bound combine `H>=1` with
+`H>=(X/A^s-1)/(C-1)`: the first suffices when X<=C A^s and the second when
+X>=C A^s. Thus `H_d(w)=Theta((w/T_d)^s)` uniformly over the whole nonterminal
+domain, with constants independent of d and w. There is no positive estimate
+of this form for terminal widths, where H=0.
+
+## The diagonal recurrence and a growing root descriptor
+
+At w=d, let t=d^(1/1000). For t>=a, `T_d=ceil(t)`,
+`T_d-1+a <= 2t`, and `floor(T_d/73) >= T_d/146 >= t/146`.
+The latter inequality follows from `floor(x)>=x/2` for x>=1. Therefore
+
+\[
+\frac{(d^{999/1000}/2)^s-1}{C-1}
+\le H_d(d)\le
+\frac{(146d^{999/1000})^s-1}{C-1},
+\qquad H_d(d)=\Theta(d^{999s/1000}).
+\]
+
+The implicit constants are independent of d. The same exponent applies
+conditionally to any family with `epsilon*d <= w(d) <= d`, for fixed
+epsilon>0. For other width families use the explicit envelope. Multiplying
+the predecessor's bracket by 999/1000 gives the inherited numerical interval
+`0.9973262127627 < 999s/1000 < 0.9973262128626`; it is not newly certified
+numerical root information.
+
+This is a diagonal statement about a two-parameter recurrence. It neither
+constructs an admitted RootPlan with w=d nor treats physical volume v as
+constant while d grows. The full physical term has the extra factor
+`N Gamma v(d)`. It does not follow that total runtime has this exponent.
+The earlier fixed-cutoff `Theta(w^s)` remains correct on its stated domain.
+
+## Exact selected-C row-division depth
+
+Define
+
+\[
+D_d(w)=0\ (w<T_d),\qquad
+D_d(w)=1+D_d(48\lfloor w/73\rfloor)\ (w\ge T_d).
+\]
+
+This is the exact maximum number of nonterminal selected-C nodes on a path,
+including the incoming node if nonterminal. Strong induction shows that D
+is nondecreasing in w: the threshold case is immediate and the child map is
+nondecreasing with argument strictly below w. Hence among all ranks the
+maximum descendant depth is attained by rank 48, which has positive
+multiplicity. This proves the recurrence from the complete tree.
+
+An equivalent inverse characterization checks the depth without expanding
+any tree. Let `B_1=T_d` and
+
+\[
+B_{j+1}=73\left\lceil B_j/48\right\rceil.
+\]
+
+Then `D_d(w)>=j` if and only if `w>=B_j`. The base case is the source cutoff.
+Inductively, another internal level requires
+`48 floor(w/73)>=B_j`, exactly equivalent to the displayed ceiling threshold.
+These thresholds increase strictly. The source's pre-remainder test is why
+`B_1` is T_d, not the next multiple of 73. For T_d=356, the first three
+thresholds are 356, 584 and 949. The verifier checks this inverse oracle
+against all finite DP depths and the giant historical maximum path.
+
+For a positive integer incoming row count R, every selected-C row division
+in this reached tree is positive and exact **if and only if**
+
+\[
+F^{D_d(w)}\mid R.
+\]
+
+Sufficiency follows since a depth-j node receives R/F^j and no path has more
+than D internal nodes. Necessity follows on an attained longest path: its D
+successive exact divisions imply divisibility by F^D. In particular the
+smallest positive row count for this arithmetic contract is F^D. This is
+not a minimum for all supplier stock or native/Ordinary internals. Sequential
+sibling invocations reuse the same quotient; the total child count does not
+create an additional stock power.
+
+There are explicit depth estimates. With rho=48/73 and a=3456/25, for w>=T_d,
+
+\[
+\left\lceil\frac{\log((w+a)/(T_d-1+a))}{\log(73/48)}\right\rceil
+\le D_d(w)\le
+1+\left\lfloor\frac{\log(w/T_d)}{\log(73/48)}\right\rfloor.
+\]
+
+Along the maximum path, `w_j <= rho^j w` and
+`w_j+a >= rho^j(w+a)`. The first terminal width is at most T_d-1;
+the last internal width is at least T_d. Substituting these two facts gives
+the displayed inequalities, with the strict threshold explaining the upper
+`1+floor`. The checker verifies their integral equivalents, using powers
+of 48 and 73, without floating-point logs.
+
+Consequently
+
+\[
+D_d(d)=\frac{999}{1000}\frac{\log d}{\log(73/48)}+O(1).
+\]
+
+For fixed F, the arithmetic row minimum therefore satisfies
+`F**D_d(d) = Theta_F(d**((999/1000)*log(F)/log(73/48)))`.
+For variable F use the exact power; the constants in `Theta_F` are not
+asserted uniform in F. This is a row-divisibility statement, not an installed
+storage improvement.
+
+In #4753's historical descriptor `d=isqrt(2**16949)`, exact integer iteration
+gives T_d=356 and D_d(d)=13997, ending at width 240. The cutoff-free
+recurrence with T=73 gives 13999, ending at 48. The original conservative
+RootPlan and its stock remain unchanged. Replacing its depth needs its own
+root-layout, padding, all-caller and admission argument.
+
+## Boundary of the result
+
+No matched D* versus B* sign is established. All retained later calls,
+candidate-only nonchild/shell/control work and the exact return credits must
+still appear in that comparison. Lower bounds on both sides do not compare
+their difference. No new recursive invoice is proposed, so the signed
+invoice preflight is not an admission substitute or a claimed improvement.
+
+Source histogram/physical correctness, actual RootPlan admissibility, stock
+construction, numerical precision, restoration, native/Ordinary implementations
+and the selected framework assumptions remain inherited or unchecked. The
+finite checker corroborates the written proof and its source descriptor
+boundary; it is not a proof-assistant derivation or production execution.
diff --git a/research/minimum-root-row-prefix/vendor/PR5515-README.md b/research/minimum-root-row-prefix/vendor/PR5515-README.md
new file mode 100644
index 0000000000..ca14cf60fd
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/PR5515-README.md
@@ -0,0 +1,131 @@
+# QQ16 parking with its global-root cutoff
+
+**Scoped proof with exact finite corroboration; no new kappa.** The literal
+historical QQ16 child backend stops at `w < 73 or w**1000 < d`, where d is
+the global root-width descriptor. This package extends Nick Petalas's
+[#4865 fixed-cutoff parking law](../qq16-parking-power-law/README.md) to that
+varying cutoff and determines the exact selected-C row-division depth.
+It answers part of that package's second open question. The complete
+matched QQ16 cost comparison remains open.
+
+Put `T_d=max(73,ceil(d**(1/1000)))`, `C=255331/7168`, `a=3456/25`, and let s
+be #4865's existing moment root. For w>=T_d, the normalized parking mass is
+bounded uniformly by
+
+\[
+\frac{((w+a)/(T_d-1+a))^s-1}{C-1}
+\le H_d(w)\le
+\frac{(w/\lfloor T_d/73\rfloor)^s-1}{C-1}.
+\]
+
+In fact `H_d(w)=Theta((w/T_d)**s)` uniformly for w>=T_d. Thus the diagonal
+recurrence has `H_d(d)=Theta(d**(999*s/1000))`, with constants independent of d.
+This concerns normalized current-bank parking volume;
+physical volume, admission and the complete cost are additional obligations.
+The fixed-cutoff theorem remains unchanged and correctly scoped.
+
+The maximum-rank path
+`w -> 48 floor(w/73)`, stopped at T_d, gives the exact division depth D_d(w).
+Equivalently, the smallest widths reaching j divisions are `B_1=T_d` and
+`B_(j+1)=73 ceil(B_j/48)`; this supplies a separate exact depth oracle.
+Every selected-C row division is positive and exact precisely when
+`(14336 Gamma)**D_d(w)` divides the positive incoming row count. At the
+historical `d=isqrt(2**16949)`, the depth is **13997**, versus the existing
+cutoff-free sufficient depth **13999**. This does not install smaller root
+stock. [PROOF.md](PROOF.md) proves the envelope, its changing-root consequence,
+the exact divisibility statement and logarithmic depth bounds.
+
+## Evidence and reproduction
+
+```sh
+python3 -B scripts/research_package.py --package research/qq16-root-cutoff-parking --check-only
+python3 -B scripts/research_package.py --package research/qq16-root-cutoff-parking
+```
+
+Expected scientific status: `PASS_QQ16_ROOT_CUTOFF_PARKING`. Python 3.12 and
+the standard library suffice. The registered normal and optimized runs are
+read-only and compare the full deterministic [RESULT.json](RESULT.json).
+Only `verify.py --write` regenerates that receipt.
+
+The checker uses exact rational dynamic programming at ten cutoffs and every
+width 0..8192, an independent breadth census on 70 boundary/large-width cases,
+30 exact 1000th-power boundaries, and all 584 rank/residue inequalities.
+It checks the full-volume cancellation and exact stock powers at three
+integer Gamma calibrations. The giant historical root is checked by a single
+maximum path and independent inverse thresholds, without constructing its
+bank, row count or full tree.
+
+The source probe extracts the unchanged `Machine.node` and `prepare_child`
+methods from authenticated bytes and runs them over exact integer descriptor
+operations. It checks cutoff equality, no repeated post-remainder test,
+child width/rows, unchanged global d and the complete spectator rectangle.
+Its Tape/Count primitives are explicitly test interpreters: this is **not**
+physical payload execution or an audit of primitive implementations. Executed
+source mutations change equality, global-root forwarding, rows and spectator
+tails; arithmetic discriminators cover a frozen cutoff, a repeated test and
+an insufficient affine shift. One-short stock is rejected on every tested
+nonterminal maximum path, and a row-count size bound is distinguished from
+exact divisibility. Dropping rank 48 underestimates the tested tree depth.
+Receipt controls reject duplicate keys and boolean/float substitutions for
+integer fields.
+
+The finite checks corroborate the written universal proof. They do not
+numerically certify a new moment root or rerun #4753's literal-word census.
+The existing root bracket is cited only for orientation. No full supplier,
+selected cold replay, Lean, Docker, native payload, hosted CI or independent
+human review is claimed.
+
+Resource limits: fixed ten-cutoff arrays of 8193 entries, breadth width at most
+65536, at most 4096 states/64 levels per census, and a 40000-step maximum-path
+cap. The largest checked root has fewer than 21000 bits. No proof-relevant
+subprocess or third-party package is used. Source pins cover every external
+input; package-local files are the remaining execution closure.
+
+## Scope and coordination
+
+Base: `32890bc5de034ab8fc93ac88ead7279a6a416d04`, priority revision 7,
+card `joint-query-controller`, refined scope in [TASK.json](TASK.json).
+The [claim is in Discussion #4744](https://github.com/CrocSwap/integer-mult-bounds/discussions/4744#discussioncomment-19173694),
+following [#4865's released result](https://github.com/CrocSwap/integer-mult-bounds/discussions/1166#discussioncomment-19133932).
+[SOURCES.json](SOURCES.json) freezes current-base bytes and the historical
+provenance. This is the original backend retained by #4166/#4753, not a new
+analysis of the currently selected #5413 supplier.
+
+No family expansion is justified by this result. The exact current-bank
+parking term is only one removed expense. Candidate-only work, other parked
+roles, restores, all retained later calls and finite control remain charged
+or explicitly unresolved. Root-dependent bounds alone cannot decide the
+complete D* versus B* inequality.
+
+## Open next questions
+
+1. Can the exact depth replace the conservative RootPlan stock exponent?
+   First bind padding, root-prefix geometry and every consumer of the original
+   depth to one admitted root family. The arithmetic divisibility result does
+   not check those contracts, and no stock replacement is installed here.
+2. What bounds every candidate-only positive interval in the nonterminal
+   D* versus B* comparison? Start from the actual unmatched Compact/native
+   interval and its full geometry in the #4744 handoff. The missing upper
+   invoice remains the decision blocker; another descendant census is not
+   sufficient. See the structured obligations in TASK.json.
+
+## Credit
+
+Prepared for commdata2338 (@commdata2338), with substantial OpenAI Codex assistance.
+
+Nick Petalas's #4865 (`8f8f518bd1a40baa30434ab18e86fd851d122b28`) supplies
+the weighted-leaf identity, two potential functions, sharp affine shift and
+fixed-cutoff exponent law. Brian/JoyboyBrian's #4753
+(`44e2c79344e0090d4e829e0dde4f533d8d0273ec`) supplies the complete histogram,
+global cutoff, fresh-row/full-bank interpretation and physical parking floor.
+Chris R/Clear1nsight's #4166/#4167/#4172/#4177 and recursive-binding work
+supply the installed caller and comparison boundaries. Jose Manuel supplies
+the original physical machinery; ywz65, Sagar Thakrar, Tekalign, Ali Romman,
+Arham Tahir and the retained source notices keep their predecessor credit.
+
+The new contribution is the cutoff-uniform theorem, changing-root consequence,
+exact selected-tree stock-depth characterization and source-bound checks.
+No literature-priority claim is made for finite-tree potentials or monotone
+path arguments. Apache-2.0. Substantial AI assistance covers derivation,
+implementation, checking and writing; no independent human or formal-kernel
+acceptance is asserted.
diff --git a/research/minimum-root-row-prefix/vendor/ROOT-PROOF.md b/research/minimum-root-row-prefix/vendor/ROOT-PROOF.md
new file mode 100644
index 0000000000..c505caecc7
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/ROOT-PROOF.md
@@ -0,0 +1,288 @@
+# Physical refinement of the selected recursive complex layer
+
+Jose Manuel (`jmbarrancoml`), with substantial OpenAI Codex assistance,
+including source-analysis agents. Apache-2.0.
+
+## Claim and retained hypotheses
+
+I implement the whole-call algorithm in PR2287, including the root return.
+I retain that contribution's quantified domain: precision p>=2,
+d=floor(p^(997/1000)), K=floor(d^(1/500)), D<=d selected axes at
+rho+jK, 0<=rho<K, complete spectator fields and arbitrary outer rows.
+Each record has r=2^Theta(p/d) Gaussian fields, with fixed positive constants;
+the address and descriptor length is O(p). At the root I accept coefficients
+in 2^-p Z[i] in the unit disk. At internal entries I allow arbitrary
+correlations and the incoming heights specified below.
+
+Under the retained selected native identities, chronological hosting proof,
+and completed ordinary B1/C0 interchange contract, I obtain the same conditional
+O(V d^(599/600)) normalized-layer bound as PR2287. I give a Count-driven
+physical interpreter for that construction, rather than a new exponent.
+I retain the source claims about elementary tape operations and the
+noncircular ordinary backend. I have not formalized their refinement or
+executed the selected O(73,2)/GL64 payload.
+
+I distinguish three kinds of evidence. I check the complete finite selected
+instruction inventory and fixed-prime admission. I execute reduced complete
+controllers against independent arithmetic oracles. I give the following
+induction and cost argument for the full source-relative construction.
+The reduced executions do not prove its universal refinement.
+
+## Finite compilation and ordinary dependency
+
+In `cohort.py` I authenticate one shared instance of the inherited Count,
+Tape, lease and primitive modules. I replace activation/recipe entry points
+with explicit adapters; I retain the inherited execution bodies. At each
+adapter I check module identity before returning the cohort. I preserve the
+frozen archives and their notices.
+
+In `production_native.py` I construct the actual Catalogue, Specifications,
+selected topology, SelectedBinding, complete mode-zero program and Ordinary
+instance, with capacity 2^24 and the unchanged Profile. I fix
+
+    q* = 213*2^80+1 = 257501199577916014212415489.
+
+In `check_prime.py` I verify the base 7 Proth certificate from PR2234 and
+the selected rational units, ranks and chart preparations. I check 636 frame
+projectors, 2,395 normalized low/high residual pairs, 111 port bases and 111
+rho15 charts. I retain the source column-order splitting rule. For a local
+64-dimensional residual, I append 56 coordinate kernel columns to the
+checked eight-dimensional split; for an idle residual I use its coordinate
+split. I build full charts from the checked matrices and coordinate
+embeddings/permutations. Multiplication by any fixed member of GL64 preserves
+invertibility. This finite argument avoids a GL64 sweep for prime admission.
+
+I leave the generated-unit and fallback correctness claims with the retained
+C0 source. The production constructor performs trial division through q*-1,
+materializes the GL64 program and allocates q*^2-scale inventories. I claim
+finite compilation, not practical compilation. In numerical fixtures I label
+the elementary q=2 backend and never substitute it for this factory.
+
+In `scalar_program.py` I lower 349 normalized literals from both complete
+R480 words. For ADD a/2^k, I copy the source into a zero third word, build
+|a| by binary Horner steps, apply k exact halvings, add with the required
+sign and clear the third word. I preserve the source at each prefix.
+SCALE uses signed powers of two. I check exact affine rows at each prefix.
+The largest program has 33 instructions, denominator 65536 and prefix L1 norm
+65537. I extend PR3098's 31-template lowering domain without changing its
+physical instruction body.
+
+In `native_program.py` I retain 24,767 events per orientation in order and
+emit 31,755 instructions per orientation. I map a directed residual to its
+right monomial, one rank-r child and its left monomial. I invert the declared
+pre/post helper wrappers and preserve endpoint directions. I retain phase
+section markers and literal identity adapters. I use the separately supplied
+backward word. I preserve scalar coefficients when lifting the unary labels
+columnwise, as in PR2287's common-label argument.
+
+## Cover and complete global dispatch
+
+I index the fixed O(73,2) cover by lexicographic row order. For an orthonormal
+prefix, let c be the remaining characteristic vector and t the remaining
+dimension. I count candidates by the affine equations specifying orthogonality
+and norm one. For odd t>1, I exclude c: after choosing c I would have a
+nonzero alternating complement and could not complete an orthonormal basis.
+For even t I exclude nothing; for t=1 I accept the final row.
+
+Thus I have 2^(t-1)-[t>1 and t odd] choices, followed by the same count in
+dimension t-1. I count bit-prefix completions by exact binary elimination,
+then rank/unrank one row at a time. This proves the indexing induction and
+the familiar cardinality
+
+    Gamma = 2^1296 product(i=1..36)(2^(2i)-1).
+
+I check the complete small groups through dimension 5 and bounded 73-dimensional
+round trips. I do not enumerate Gamma. These matrices and ordinals belong
+to fixed finite control, independent of numerical input precision.
+
+In `selected_binding.py` I bind all 482 chronological events, 144 local calls,
+101,376 owner entries and 10,002 emitted helper charts. For a common cover d
+and owner chart sigma, I select the physical owner g=d sigma^-1. The archive
+stores columns of sigma; I use them as rows of its inverse. I gather the
+whole owner packet, apply P_d^-1 and the pulled-back data entrance alignment,
+execute the complete local program, then apply its exit alignment and P_d.
+I apply no data-family Pauli to helper packets.
+
+For an idle child I use the exact unconsumed axis suffix and complete its
+orthogonal chart. I perform its child call before X_(g theta). I retain 6,822
+nonzero translations after hosting consumed the positive-rank part.
+I keep bridges at their physical family/cover positions, perform terminal
+Y translations before (X,Y)->(Y,-X), and finally use the output-coordinate
+mask delta(g)_i=(wt(row_i(g))-1)/2 mod2. I do not multiply that final mask
+by g a second time.
+
+I retain the selected common-label, untouched-window and tensor identities
+from PR2287 and the archived sources. Those identities establish that this
+complete global dispatch returns C^(tensor 73f) on each live row. I check
+the compiled child histogram against
+
+    {1:349604,2:60192,3:62585,4:20448,5:11808,7:7,8:1152,48:4866}.
+
+I account for 70,032 fixed subgroups per cover. Empty identity corrections
+need no payload scan; I preserve their place in the finite schedule.
+
+## One active node and physical returns
+
+I store a node rectangle in the order
+
+    [P][R][front][H][H][before][e*K][after][H][back][r Gaussian fields].
+
+In `bank_packets.py` I scan the complete current bank to gather the selected
+family/cover packets. I keep the current bank until I have constructed the
+complete replacement, then commit that replacement. I preserve the entire
+unused-row and spectator rectangle. At smaller global groups I leave the
+unused roles in the fixed 704-packet inventory empty.
+
+In `machine.py` I stop at e<73 or e^1000<d. Otherwise I process the leftmost
+e mod73 selected chunks with the exact leaf, retain them as spectators and
+set f=floor(e/73). I divide the row count by L=14336 Gamma and require a
+positive exact quotient U. At a rank-r child I set e'=rf, R'=U and append
+(73-r)fK bits to `after`. I preserve the complete packet volume v=V/L.
+I keep d,K,G,H and the coefficient grid global.
+
+Before descent I close scalar, leaf, monomial and native scratch. I encode
+the parent's finite root/event/subgroup/cover/PC/target/rank header and all
+Count descriptors, then park the fixed roles on a physical stack. I encode
+body symbols in four bits and use separate role/frame delimiters. I copy
+the child capsule into the same active roles and continue the interpreter
+loop. I retain no Python recursive continuation.
+
+At return I move the child's complete result to a protected tape, erase the
+active roles, restore one parent frame and check its exact child instruction.
+I replace that child packet and resume at the saved next PC. I reconstruct
+the finite group from source control alone. Strong induction on e closes
+the endpoint: r<=48<73, previous children have completed endpoints, and the
+current child receives only its own copied input and descriptors. I never
+read a buried ancestor during a child. The parent may contain correlated
+dirty families, and its private centres follow the literal COPY/CLEAR word.
+
+At root return I require an empty continuation stack and empty owned work.
+I preserve the borrowed source and descriptors, including after the tested
+short-packet and insufficient-row rejections. I make no promise to recover
+from arbitrary corruption of an inherited primitive's private state.
+
+## Root planning, normalization and rounding
+
+In `root_plan.py` I compute the PR2287 reservations with encoded arithmetic:
+
+    G=4 ceil(log2 p)+6, H=dG,
+    D0(e)=0 for e<73, otherwise 1+D0(48 floor(e/73)),
+    q0=ceil(log2 L)D0(d), qF=ceil(2H/K), qB=ceil(H/K), Q0=q0+qF+qB.
+
+I obtain floor rational powers from the inherited ceiling root by comparing
+with the exact target; I saturate at target+1 so that I retain strict
+overshoot information. I close the fixed expression temporaries before
+entering recursive execution.
+
+I also discharge the Compact repair inequality at each fast input. Put
+l=ceil(log2 p). Since Q0>=qF+qB>=3H/K=3dG/K, the conditions D>Q0 and
+D<=d give K>3G. Therefore
+
+    K>=3G+1=12l+19>8l+16=G+4l+10.
+
+I meet the sufficient inequality in the credited PR3055 Compact proof
+without adding an execution cutoff. I also have 3H<dK<=p^.998994<=p,
+so the reserved compact fields fit the address domain. At f=1 I bypass
+Compact; below the ordinary fitted range I use its elementary fallback.
+I still require the long-record hypothesis to absorb descriptor/repair
+setup. For shorter records I retain the unabsorbed primitive invoice.
+
+For D<=Q0 I use the direct leaf. Otherwise I process the first q0+qF and
+last qB axes, reserve the complete row range R0=2^(q0K), and pad it once
+to a multiple of L^D0(d). Since R0>=L^D0(d), I increase volume by less than
+two. I keep outer rows and the left spectator field as complete prefixes.
+I carve two front H-bit fields and one back H-bit field, then call Machine
+on the remaining D-Q0 chunks. After its endpoint I verify that padded rows
+are zero before removing them. At each child U retains the required stock,
+by D0(rf)<=D0(e)-1. I restore the original address rectangle.
+
+I choose Delta=2^210000 d once and represent components with
+h=p+2Delta+3 bits on the grid2^-(p+Delta). I append Delta low zeros and
+Delta+1 sign-extension bits to each p+2-bit input component. In `root_layer.py`
+I execute
+
+    S_D, C^(tensor D), S_D, multiplication by b^D,
+    b=(1-i)/2,
+
+on that one grid. I reuse PR3127's Count-driven one-pass normalization.
+The retained identity gives H0^(tensor D), where H0=[[1,1],[1,-1]]/2.
+I truncate each component toward zero only after the whole root. For a
+negative quotient with discarded nonzero bits, I add one before checking
+output headroom; checking before that correction would reject valid boundary
+values. I preserve the unit disk and incur error below sqrt(2)2^-p, since
+H0 has row L1 norm one and componentwise truncation decreases absolute values.
+
+## Inventory, height, time and space
+
+I allocate 678 tapes outside Machine, 3,348 complex-controller tapes excluding
+the shared native backend, and
+
+    6(C+1)+Wb+Sb+2q^2+417
+
+native tapes, with C=2^24,Wb=28416,Sb=662. I include the two numerical-codec
+tapes that use dictionary storage. In total I own 2q^2+100696823 physical
+tapes; the caller supplies eight input ports. I allocate no extra tape
+inventory per cover matrix, scalar literal or recursive depth. I count
+fixed source tables separately from numerical work. I do not reuse PR2287's
+720-slot estimate for this implementation.
+
+The two local words require 80,397 and 80,421 scalar microinstructions.
+Across 80 forward and 64 backward calls, plus their standalone COPY/CLEAR,
+I charge 11,581,648 passes per cover before bridges, within PR2287's
+20,936,640 scalar allowance. Each Horner prefix has height at most
+max(bit_length(|a|),k), within the credited source charge. Monomial movements
+and unit phases add no coefficient height.
+
+I retain s=1041408 Gamma,E=2^100000,B=s+E. With the actual inventory, I
+check the enlarged conservative literal allowance below E. Before the one
+unfinished child, I charge previous children only by their completed widths.
+The PR2287 induction therefore remains
+
+    A(e)<=8e at a leaf;
+    A(e)<=A(48f)+sf+E internally;
+    A(e)<=2Be, and A_layer<2^210000 d.
+
+I check the strict integer guard inequalities. Hence each exact half discards
+zeros on the common grid, and signed headroom covers each interpreted
+coefficient prefix. I interpret native bit-work as coefficients only after
+the completed bit operation returns. I round no child result.
+
+I charge complete bank scans, replacement copies and parking, in addition
+to primitive work. Their finite multiplicities change constants. With the
+retained ordinary exponent tau=.99830289, I obtain per-node nonrecursive
+cost O(V((e log p)^tau+1)). I use the unchanged child histogram and the
+retained strict sigma=.99833 moment. With cutoff beta=.001 I obtain internal
+exponent .99832997289, leaf exponent .99833167 and reservation exponent .998.
+Each lies below249583/250000<599/600, leaving room for the logarithmic factors.
+I retain the long-record hypothesis to pay polynomial descriptor and per-row
+preparation costs. I claim no new moment or multiplication exponent.
+
+At a child cut I park at most V+712(V/L) payload bits and19 metadata/header
+roles. I use 732 role delimiters and one frame delimiter. Along a branch the
+payload volumes are V/L^j, so parked payload occupies at most
+
+    4(1+712/L)V/(1-1/L).
+
+I also charge the root's retained input copy, replacement bank, child capsule
+and protected output. With the inherited Compact/native space contract and
+long records, I use O_q(V)+F_q space. I prove this for occupied/visited tape
+regions, not garbage-collector behavior. The Tape emulator never shrinks its
+backing list on clear; across repeated roots its allocation follows the largest
+historical call. At blank return I establish erased work, not reclaimed host
+memory.
+
+## Evidence limits and next obligations
+
+I execute complete reduced recursive C fixtures, including two nested levels,
+and direct/reduced-fast normalized roots. I compare them with independently
+written Gaussian and rational Walsh oracles. I check selected compilation,
+small complete covers, signed truncation boundaries, retained borrows and
+named cleanup failures with assertions disabled.
+
+I have not executed a production-guard root, the complete O73 payload or the
+GL64 native factory. I have not emitted a literal universal transition table
+or obtained independent human or proof-assistant validation of this refinement.
+I retain the native, hosting, analytic-transfer and outer integer-packing
+obligations at their credited scope. A reviewer should examine the refinement
+induction and source-relative factory before using this implementation in a
+complete multiplication theorem.
diff --git a/research/minimum-root-row-prefix/vendor/machine.py b/research/minimum-root-row-prefix/vendor/machine.py
new file mode 100644
index 0000000000..92f9467ffd
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/machine.py
@@ -0,0 +1,477 @@
+# SPDX-License-Identifier: Apache-2.0
+"""One active complex node and a physical stack of parent continuations.
+
+I adapt PR2809's finite-PC protocol to Count descriptors and Gaussian packets.
+The selected binding supplies finite source groups; it never receives payloads.
+"""
+import cohort
+api = cohort.activate()
+from bank_packets import BankPackets, skip
+from cardinal_counts import Count, positive
+from compact_counts import power_two
+from encoded import compare, divide, fixed_power, subtract
+from monomial_packets import MonomialPackets
+from parking import BODY, FiniteFields, Parking, transfer
+from records import Tape
+from scalar_packets import FullScalarEngine
+from scalar_words import require_zero
+from scratch_pool import ScratchPool
+from session import (OuterScope, borrowed_count, borrowed_tape, erase_marker,
+                     initialize_marker, sealed_constructors)
+from stream import Counter
+from words import BLANK, LEFT, need
+
+INPUTS = ("prefixes", "rows", "front", "compact_bits", "before", "width", "after", "back",
+          "spacing", "guard", "residue", "component_bits", "coefficients", "root_width")
+DERIVED = ("columns", "unused", "row_bits", "gaussians")
+LEAF_NAMES = ("front", "u", "t", "before", "active", "after", "b", "back")
+
+
+def origin(tape):
+    """Rearm an owned marker at a known canonical head, preserving its body."""
+    tape.step(-1)
+    try:
+        need(tape.read() in (LEFT, BLANK), "canonical owned origin")
+        if tape.read() == BLANK:
+            tape.write(LEFT)
+    finally:
+        tape.step(1)
+
+
+def copy_symbols(source, target):
+    source = borrowed_tape(source)
+    need(source is not target, "distinct preserved-copy ports")
+    source.rewind()
+    target.clear()
+    while source.read() != BLANK:
+        symbol = source.read()
+        need(symbol in BODY, "dense copied role")
+        target.append(symbol)
+        source.step(1)
+    source.rewind()
+    target.rewind()
+
+
+class Machine:
+    def __init__(self, binding, native, catalogue, observe=None):
+        self.binding = binding
+        self.bank = BankPackets(binding.families, binding.cover.size, binding.slots)
+        self.private = tuple(Tape() for _ in range(binding.private))
+        self.roles = {name: Tape() for name in ("current", "header", *INPUTS, *DERIVED)}
+        self.capsule = {name: Tape() for name in ("current", *INPUTS)}
+        self.output = Tape()
+        self.pool = ScratchPool(256)
+        self.scope = OuterScope(self.pool)
+        self.scalar = FullScalarEngine(catalogue)
+        self.leaf = api["coefficient_engine"].CoefficientEngine(LEAF_NAMES, "active")
+        vectors = tuple("v" + str(i) for i in range(binding.dimension))
+        names = ("front", "u0", "u", "t0", "t", "before", *vectors, "after", "b0", "b", "back")
+        self.monomial = MonomialPackets(names, vectors, native)
+        self.parked = (*self.roles.values(), *self.bank.packets, *self.private)
+        self.parking = Parking(self.parked)
+        groups = max(1, *(binding.group_count(i) for i in range(len(binding.events))))
+        self.header = FiniteFields((2, len(binding.events), groups, binding.cover.size,
+                                   65536, binding.slots + binding.private, binding.dimension))
+        self.root = True
+        self.event = self.subgroup = self.cover_index = self.pc = 0
+        self.group = None
+        self.mode = "closed"
+        self.closed = True
+        self.observe = observe  # Checker-only. Its return value never affects execution.
+
+    def c(self, name):
+        value = object.__new__(Count)
+        value.tape = self.roles[name]
+        return value
+
+    def save(self, value, name):
+        try:
+            transfer(value.tape, self.roles[name])
+        finally:
+            value.close()
+
+    def packet(self, index):
+        need(type(index) is int and 0 <= index < self.binding.slots + self.binding.private,
+             "compiled packet role")
+        return self.bank.packets[index] if index < self.binding.slots else self.private[index - self.binding.slots]
+
+    def primitive_boundary(self):
+        self.pool.empty()
+        need(self.scalar.closed and not self.scalar.pool.live and self.scalar.output.read() == BLANK,
+             "scalar closes before recursive cut")
+        need(self.leaf.closed and not self.leaf.pool.live and self.leaf.output.read() == BLANK,
+             "leaf closes before recursive cut")
+        need(self.monomial.closed and not self.monomial.pool.live and self.monomial.output.read() == BLANK
+             and self.monomial.compact.closed and self.monomial.compact.binary.native.closed,
+             "monomial closes before recursive cut")
+
+    def shape(self):
+        active = Count.product(self.c("width"), self.c("spacing"))
+        bits = Count(self.c("compact_bits"))
+        records = row_bits = None
+        try:
+            bits.multiply_small(3)
+            for name in ("front", "before", "after", "back"):
+                bits.add(self.c(name))
+            bits.add(active)
+            records = power_two(bits)
+            row_bits = Count.product(records, self.c("coefficients"))
+            expanded = Count.product(row_bits, self.c("component_bits"))
+            expanded.multiply_small(2)
+            self.save(expanded, "row_bits")
+        finally:
+            for value in (active, bits, records, row_bits):
+                if value is not None:
+                    value.close()
+
+    def complete_extent(self):
+        rows = Count.product(self.c("prefixes"), self.c("rows"))
+        try:
+            return Count.product(rows, self.c("row_bits"))
+        finally:
+            rows.close()
+
+    def apply_leaf(self, width, before, after):
+        if width.zero():
+            return
+        active = Count.product(width, self.c("spacing"))
+        rows = Count.product(self.c("prefixes"), self.c("rows"))
+        widths = tuple(Count(v) for v in (self.c("front"), self.c("compact_bits"), self.c("compact_bits"),
+                                        before, active, after, self.c("compact_bits"), self.c("back")))
+        try:
+            with self.scope.suspended():
+                returned = self.leaf.run_leaf(self.roles["current"], tuple(borrowed_count(v) for v in widths),
+                    *(borrowed_count(v) for v in (width, self.c("spacing"), self.c("residue"),
+                      self.c("component_bits"), self.c("coefficients"), rows)))
+            transfer(returned, self.roles["current"])
+            erase_marker(returned)
+        finally:
+            for value in (*widths, active, rows):
+                value.close()
+
+    def node(self):
+        dimension = Count.literal(self.binding.dimension)
+        test = extent = columns = removed = rest = suffix = shift = divisor = unused = remainder = None
+        try:
+            for name in ("prefixes", "rows", "spacing", "guard", "component_bits", "coefficients", "root_width"):
+                positive(self.c(name))
+            need(compare(self.c("width"), self.c("root_width")) <= 0, "node within global width")
+            self.shape()
+            extent = self.complete_extent()
+            self.roles["current"].rewind()
+            skip(self.roles["current"], extent)
+            need(self.roles["current"].read() == BLANK, "complete node input")
+            self.roles["current"].rewind()
+            if self.c("width").zero() or compare(self.c("width"), dimension) < 0:
+                self.apply_leaf(self.c("width"), self.c("before"), self.c("after"))
+                self.mode = "return"
+                return
+            test = fixed_power(self.c("width"), 1000, self.c("root_width"))
+            if compare(test, self.c("root_width")) < 0:
+                self.apply_leaf(self.c("width"), self.c("before"), self.c("after"))
+                self.mode = "return"
+                return
+            columns = Count(self.c("width"))
+            delta = columns.divide_small(self.binding.dimension)
+            if delta:
+                removed = Count.literal(delta)
+                rest = subtract(self.c("width"), removed)
+                suffix = Count.product(rest, self.c("spacing"))
+                suffix.add(self.c("after"))
+                self.apply_leaf(removed, self.c("before"), suffix)
+                shift = Count.product(removed, self.c("spacing"))
+                shift.add(self.c("before"))
+                self.save(shift, "before")
+                shift = None
+                self.save(rest, "width")
+                rest = None
+            self.save(columns, "columns")
+            columns = None
+            divisor = Count.literal(self.binding.families * self.binding.cover.size)
+            unused, remainder = divide(self.c("rows"), divisor)
+            need(remainder.zero() and not unused.zero(), "complete fresh row divisor at node")
+            self.save(unused, "unused")
+            unused = None
+            local_bits = Count.product(self.c("prefixes"), self.c("unused"))
+            local_extent = Count.product(local_bits, self.c("row_bits"))
+            local_bits.close()
+            divisor2 = Count(self.c("component_bits"))
+            divisor2.multiply_small(2)
+            gaussian_count, rem2 = divide(local_extent, divisor2)
+            try:
+                need(rem2.zero(), "complete Gaussian local packet")
+                self.save(gaussian_count, "gaussians")
+                gaussian_count = None
+            finally:
+                if gaussian_count is not None:
+                    gaussian_count.close()
+                local_extent.close()
+                divisor2.close()
+                rem2.close()
+            self.event = self.subgroup = self.cover_index = self.pc = 0
+            self.group = None
+            self.mode = "group"
+        finally:
+            for value in (dimension, test, extent, columns, removed, rest, suffix, shift, divisor, unused, remainder):
+                if value is not None:
+                    value.close()
+
+    def scalar_step(self, target, source, key):
+        self.scalar.select(key)
+        with self.scope.suspended():
+            returned = self.scalar.run(self.packet(target), None if source is None else self.packet(source),
+                                       borrowed_count(self.c("component_bits")), borrowed_count(self.c("gaussians")))
+        transfer(returned, self.packet(target))
+        erase_marker(returned)
+
+    def packet_extent(self):
+        extent = Count.product(self.c("gaussians"), self.c("component_bits"))
+        extent.multiply_small(2)
+        return extent
+
+    def zero_step(self, target):
+        need(target >= self.binding.slots, "only compiled private logical CLEAR")
+        extent = self.packet_extent()
+        remaining = Counter(extent)
+        tape = self.packet(target)
+        tape.clear()
+        try:
+            while not remaining.finished:
+                tape.append(0)
+                remaining.decrement()
+        finally:
+            tape.rewind()
+            remaining.close()
+            extent.close()
+
+    def copy_step(self, target, source):
+        need(target >= self.binding.slots and target != source, "compiled private COPY")
+        extent = self.packet_extent()
+        try:
+            require_zero(self.packet(target), extent)
+            copy_symbols(self.packet(source), self.packet(target))
+        finally:
+            extent.close()
+
+    def exchange_step(self, x, y):
+        self.scalar.select(("scale", -1, 1))
+        with self.scope.suspended():
+            returned = self.scalar.run(self.packet(x), None, borrowed_count(self.c("component_bits")),
+                                       borrowed_count(self.c("gaussians")))
+        transfer(self.packet(y), self.packet(x))
+        transfer(returned, self.packet(y))
+        erase_marker(returned)
+
+    def monomial_step(self, target, key, inverse):
+        self.monomial.select(self.group.recipes[key])
+        one = Count.literal(1)
+        columns = compact = extra = wide = rows = None
+        widths = ()
+        try:
+            columns = subtract(self.c("columns"), one)
+            compact = Count.product(columns, self.c("guard"))
+            extra = subtract(self.c("compact_bits"), compact)
+            wide = Count.product(self.c("columns"), self.c("spacing"))
+            rows = Count.product(self.c("prefixes"), self.c("unused"))
+            template = (self.c("front"), extra, compact, extra, compact, self.c("before"),
+                        *((wide,) * self.binding.dimension), self.c("after"), extra, compact, self.c("back"))
+            widths = tuple(Count(value) for value in template)
+            with self.scope.suspended():
+                returned = self.monomial.run(self.packet(target), tuple(borrowed_count(v) for v in widths),
+                    *(borrowed_count(v) for v in (self.c("columns"), self.c("spacing"), self.c("guard"),
+                      self.c("residue"), self.c("component_bits"), self.c("coefficients"), rows)), inverse=inverse)
+            transfer(returned, self.packet(target))
+            erase_marker(returned)
+        finally:
+            for value in (*widths, one, columns, compact, extra, wide, rows):
+                if value is not None:
+                    value.close()
+
+    def next_group(self):
+        while self.event < len(self.binding.events):
+            count = self.binding.group_count(self.event)
+            if self.subgroup >= count:
+                self.event += 1
+                self.subgroup = self.cover_index = 0
+                continue
+            if self.cover_index >= self.binding.cover.size:
+                self.cover_index = 0
+                self.subgroup += 1
+                continue
+            group = self.binding.group(self.event, self.subgroup, self.cover_index)
+            need(len(group.code) < 65536, "finite group program-counter bound")
+            if not group.code:
+                self.cover_index += 1
+                continue
+            self.group = group
+            self.bank.select(group.keys)
+            with self.scope.suspended():
+                self.bank.gather(self.roles["current"], *(borrowed_count(self.c(name))
+                                  for name in ("prefixes", "unused", "row_bits")))
+            for tape in self.private:
+                origin(tape)
+                tape.clear()
+            self.pc = 0
+            return
+        self.mode = "return"
+
+    def finish_group(self):
+        extent = self.packet_extent()
+        try:
+            for tape in self.private:
+                if tape.read() != BLANK:
+                    require_zero(tape, extent)
+                tape.clear()
+        finally:
+            extent.close()
+        with self.scope.suspended():
+            self.bank.scatter(self.roles["current"], *(borrowed_count(self.c(name))
+                              for name in ("prefixes", "unused", "row_bits")))
+            self.bank.commit(self.roles["current"])
+        self.group = None
+        self.cover_index += 1
+        self.pc = 0
+
+    def prepare_child(self, target, rank):
+        need(self.group is not None and self.bank.state == "gathered", "child belongs to active group")
+        need(type(rank) is int and 0 < rank < self.binding.dimension, "source child rank contracts")
+        width = Count(self.c("columns"))
+        if rank > 1:
+            width.multiply_small(rank)
+        tail = Count(self.c("columns"))
+        if self.binding.dimension - rank > 1:
+            tail.multiply_small(self.binding.dimension - rank)
+        after = Count.product(tail, self.c("spacing"))
+        try:
+            need(not width.zero() and compare(width, self.c("width")) < 0, "strict complex child contraction")
+            after.add(self.c("after"))
+            copy_symbols(self.packet(target), self.capsule["current"])
+            for name in INPUTS:
+                value = self.c("unused") if name == "rows" else width if name == "width" else after if name == "after" else self.c(name)
+                copy_symbols(value.tape, self.capsule[name])
+            self.header.write(self.roles["header"], (int(self.root), self.event, self.subgroup,
+                self.cover_index, self.pc + 1, target, rank))
+        finally:
+            width.close()
+            tail.close()
+            after.close()
+
+    def enter_child(self):
+        self.primitive_boundary()
+        for tape in self.parked:
+            origin(tape)
+        self.parking.park()
+        for name, tape in self.capsule.items():
+            transfer(tape, self.roles[name])
+        self.bank.state = "closed"
+        self.bank.source = None
+        self.bank.selection = None
+        self.group = None
+        self.root = False
+        self.mode = "node"
+        self.event = self.subgroup = self.cover_index = self.pc = 0
+        if self.observe:
+            self.observe(self, "enter")
+
+    def return_node(self):
+        self.primitive_boundary()
+        need(self.output.read() == BLANK, "consume preceding complex output")
+        origin(self.output)
+        transfer(self.roles["current"], self.output)
+        for tape in self.parked:
+            origin(tape)
+            tape.clear()
+        self.bank.state = "closed"
+        self.bank.source = None
+        self.bank.selection = None
+        if self.root:
+            self.parking.empty()
+            self.closed = True
+            self.mode = "closed"
+            return True
+        self.parking.restore()
+        root, self.event, self.subgroup, self.cover_index, self.pc, target, rank = self.header.read(self.roles["header"])
+        self.roles["header"].clear()
+        self.root = bool(root)
+        self.group = self.binding.group(self.event, self.subgroup, self.cover_index)
+        need(0 < self.pc <= len(self.group.code) and
+             self.group.code[self.pc - 1][0] == "child" and
+             self.group.code[self.pc - 1][2:] == (target, rank), "return matches exact parent child instruction")
+        transfer(self.output, self.packet(target))
+        self.bank.selection = {key: slot for slot, key in enumerate(self.group.keys)}
+        self.bank.source = self.roles["current"]
+        self.bank.state = "gathered"
+        self.mode = "group"
+        if self.observe:
+            self.observe(self, "return")
+        return False
+
+    def discard(self):
+        for tape in (*self.parked, *self.capsule.values(), self.output, self.bank.output):
+            origin(tape)
+            tape.clear()
+        self.parking.stack.clear()
+        self.parking.reverse.clear()
+        self.bank.state = "closed"
+        self.bank.source = self.bank.selection = None
+        self.group = None
+        self.mode = "closed"
+        self.closed = True
+
+    def run(self, payload, descriptors):
+        need(self.closed and self.output.read() == BLANK and set(descriptors) == set(INPUTS),
+             "closed prepared complex entry and complete descriptors")
+        self.parking.empty()
+        source = borrowed_tape(payload)
+        need(source not in self.parked and source is not self.output, "borrowed complex input is separate")
+        need(all(isinstance(descriptors[name], Count) for name in INPUTS), "encoded prepared descriptor")
+        self.root, self.closed, self.mode = True, False, "node"
+        self.group = None
+        try:
+            copy_symbols(source, self.roles["current"])
+            for name in INPUTS:
+                copy_symbols(descriptors[name].tape, self.roles[name])
+            while True:
+                child = False
+                with sealed_constructors(), self.scope.installed():
+                    if self.mode == "node":
+                        self.node()
+                    elif self.mode == "group":
+                        if self.group is None:
+                            self.next_group()
+                        elif self.pc == len(self.group.code):
+                            self.finish_group()
+                        else:
+                            op = self.group.code[self.pc]
+                            kind = op[0]
+                            if kind == "scalar":
+                                self.scalar_step(*op[2:])
+                            elif kind == "zero":
+                                self.zero_step(op[2])
+                            elif kind == "copy":
+                                self.copy_step(*op[2:])
+                            elif kind == "monomial":
+                                self.monomial_step(*op[2:])
+                            elif kind == "exchange":
+                                self.exchange_step(*op[2:])
+                            elif kind == "child":
+                                self.prepare_child(*op[2:])
+                                child = True
+                            else:
+                                need(kind in ("identity", "marker"), "implemented physical instruction")
+                            if not child:
+                                self.pc += 1
+                    else:
+                        need(self.mode == "return", "finite complex controller state")
+                self.pool.empty()
+                if child:
+                    self.enter_child()
+                elif self.mode == "return" and self.return_node():
+                    source.rewind()
+                    return self.output
+        except BaseException:
+            for tape in (*self.roles.values(), *self.capsule.values()):
+                tape.rewind()
+            self.discard()
+            source.rewind()
+            raise
diff --git a/research/minimum-root-row-prefix/vendor/root_layer.py b/research/minimum-root-row-prefix/vendor/root_layer.py
new file mode 100644
index 0000000000..389efd17af
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/root_layer.py
@@ -0,0 +1,160 @@
+# SPDX-License-Identifier: Apache-2.0
+"""Physical root execution of b**D S_D C_D S_D with one final rounding."""
+import cohort
+api = cohort.activate()
+from cardinal_counts import Count
+from encoded import subtract
+from grid_boundary import GridBoundary
+from machine import Machine, origin
+from parking import transfer
+from records import Tape
+from root_plan import RootPlan
+from root_streams import PhaseSweep, RowPadding
+from scratch_pool import ScratchPool
+from session import OuterScope, borrowed_count, borrowed_tape, erase_marker, sealed_constructors
+from words import BLANK, need
+
+
+class RootLayer:
+    def __init__(self, binding, native, catalogue, plan=None, observe=None):
+        self.plan = plan if plan is not None else RootPlan(
+            binding.dimension, binding.maximum_rank, binding.families * binding.cover.size)
+        self.machine = Machine(binding, native, catalogue, observe)
+        self.grid = GridBoundary()
+        self.phase = PhaseSweep()
+        self.padding = RowPadding()
+        self.normalizer = api["normalizer"].Normalizer()
+        self.leaf = api["coefficient_engine"].CoefficientEngine(("left", "active", "right"), "active")
+        self.pool = ScratchPool(32)
+        self.scope = OuterScope(self.pool)
+        self.current, self.output = Tape(), Tape()
+        self.closed = True
+
+    def c(self, name):
+        return self.plan.count(name)
+
+    def accept(self, returned):
+        transfer(returned, self.current)
+        erase_marker(returned)
+
+    def apply_phase(self):
+        self.accept(self.phase.run(self.current, *(self.c(name) for name in
+            ("left", "selected", "right", "K", "residue", "work_bits", "coefficients", "outer_rows"))))
+
+    def apply_leaf(self, left, width, right):
+        if width.zero():
+            return
+        active = Count.product(width, self.c("K"))
+        try:
+            with self.scope.suspended():
+                returned = self.leaf.run_leaf(self.current,
+                    tuple(borrowed_count(v) for v in (left, active, right)),
+                    *(borrowed_count(v) for v in (width, self.c("K"), self.c("residue"),
+                      self.c("work_bits"), self.c("coefficients"), self.c("outer_rows"))))
+            self.accept(returned)
+        finally:
+            active.close()
+
+    def reserved_leaves(self):
+        prefix = tail = suffix = left = None
+        try:
+            prefix = Count(self.c("q0"))
+            prefix.add(self.c("qF"))
+            tail = subtract(self.c("selected"), prefix)
+            suffix = Count.product(tail, self.c("K"))
+            suffix.add(self.c("right"))
+            self.apply_leaf(self.c("left"), prefix, suffix)
+            tail.close()
+            tail = subtract(self.c("selected"), self.c("qB"))
+            left = Count.product(tail, self.c("K"))
+            left.add(self.c("left"))
+            self.apply_leaf(left, self.c("qB"), self.c("right"))
+        finally:
+            for value in (prefix, tail, suffix, left):
+                if value is not None:
+                    value.close()
+
+    def fast_core(self):
+        # Root scratch has closed before the recursive machine owns execution.
+        self.pool.empty()
+        self.accept(self.padding.run(self.current, *(self.c(name) for name in
+            ("prefixes", "original_rows", "padded_rows", "row_bits"))))
+        names = dict(prefixes="prefixes", rows="padded_rows", front="core_front", compact_bits="H",
+                     before="zero", width="core_width", after="zero", back="core_back", spacing="K",
+                     guard="G", residue="residue", component_bits="work_bits", coefficients="coefficients",
+                     root_width="d")
+        self.accept(self.machine.run(self.current, {name: self.c(source) for name, source in names.items()}))
+        self.accept(self.padding.run(self.current, *(self.c(name) for name in
+            ("prefixes", "original_rows", "padded_rows", "row_bits")), remove=True))
+
+    def run(self, payload, precision, selected, left, right, coefficients, outer_rows, residue):
+        """Borrow p-grid Gaussian records and encoded descriptors; return p-grid records.
+
+        The selected production plan fixes the source constants. Checkers may
+        inject an explicitly labelled reduced plan to exercise the same branch.
+        The theorem assumes the input unit disk and the native source contracts.
+        """
+        need(self.closed and self.output.read() == BLANK and self.current.read() == BLANK,
+             "consume previous complete root output")
+        source = borrowed_tape(payload)
+        need(source not in (self.current, self.output), "distinct borrowed root input")
+        origin(self.output)
+        self.closed = False
+        high = None
+        try:
+            self.plan.compute(precision, selected, left, right, coefficients, outer_rows, residue)
+            with sealed_constructors(), self.scope.installed():
+                high = Count(self.c("delta"))
+                high.increment()
+                with self.scope.suspended():
+                    returned = self.grid.expand(source, self.c("input_bits"), self.c("delta"),
+                                                borrowed_count(high), self.c("gaussians"))
+                self.accept(returned)
+                high.close()
+                high = None
+            self.pool.empty()
+            self.apply_phase()
+            with sealed_constructors(), self.scope.installed():
+                if self.plan.fast:
+                    self.reserved_leaves()
+                else:
+                    self.apply_leaf(self.c("left"), self.c("selected"), self.c("right"))
+            self.pool.empty()
+            if self.plan.fast:
+                self.fast_core()
+            self.apply_phase()
+            self.accept(self.normalizer.run(self.current, self.c("work_bits"),
+                                           self.c("gaussians"), self.c("selected")))
+            returned = self.grid.truncate(self.current, self.c("work_bits"), self.c("delta"),
+                                          self.c("input_bits"), self.c("gaussians"))
+            transfer(returned, self.output)
+            erase_marker(returned)
+            self.current.clear()
+            return self.output
+        except BaseException:
+            self.current.clear()
+            self.output.clear()
+            raise
+        finally:
+            if high is not None:
+                high.close()
+            self.pool.empty()
+            self.plan.clear()
+            source.rewind()
+            self.closed = True
+
+
+def selected_layer(q=None):
+    """Compile the selected source-relative construction for an admissible fixed q.
+
+    Full selected finite compilation is intentionally not a local fixture.
+    Its q/GL64-scale objects are finite constants in the source construction.
+    """
+    from production_native import PRIME, build_native
+    from scalar_program import compile_catalogue
+    from selected_binding import SelectedBinding
+    from selected_source import load
+    data = load()
+    binding = SelectedBinding(data)
+    catalogue, _ = compile_catalogue(data["programs"])
+    return RootLayer(binding, build_native(PRIME if q is None else q), catalogue)
diff --git a/research/minimum-root-row-prefix/vendor/root_plan.py b/research/minimum-root-row-prefix/vendor/root_plan.py
new file mode 100644
index 0000000000..78390164c3
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/root_plan.py
@@ -0,0 +1,222 @@
+# SPDX-License-Identifier: Apache-2.0
+"""Encoded root reservations and precision for PR2287's layer construction."""
+import cohort
+cohort.activate()
+from cardinal_counts import Count, positive
+from compact_counts import power_two
+from encoded import atom_width, compare, divide, fixed_power, subtract
+from machine import copy_symbols
+from records import Tape
+from scratch_pool import ScratchPool
+from session import OuterScope, sealed_constructors
+from stream import Counter
+from words import RIGHT, need
+
+
+def floor_power(value, numerator, denominator):
+    need(type(numerator) is int and type(denominator) is int and
+         0 < numerator <= denominator, "fixed fractional exponent")
+    ceiling = atom_width(value, numerator, denominator)
+    target = fixed_power(value, numerator)
+    cap = Count(target)
+    cap.increment()
+    power = one = None
+    try:
+        # Saturating at target would confuse a strict overshoot with equality.
+        power = fixed_power(ceiling, denominator, cap)
+        need(compare(power, target) >= 0, "upper integral root")
+        if compare(power, target) > 0:
+            one = Count.literal(1)
+            return subtract(ceiling, one)
+        return Count(ceiling)
+    finally:
+        for item in (ceiling, target, cap, power, one):
+            if item is not None:
+                item.close()
+
+
+def ceil_log2(value):
+    positive(value)
+    digits = Count.literal(0)
+    ones = 0
+    value.rewind()
+    try:
+        while value.read() != RIGHT:
+            bit = value.read()
+            need(bit in (0, 1), "canonical logarithm digits")
+            ones = min(2, ones + bit)
+            digits.increment()
+            value.step(1)
+        if ones == 1:
+            one = Count.literal(1)
+            try:
+                return subtract(digits, one)
+            finally:
+                one.close()
+        return Count(digits)
+    finally:
+        value.rewind()
+        digits.close()
+
+
+def ceil_divide(numerator, denominator):
+    quotient, remainder = divide(numerator, denominator)
+    try:
+        if not remainder.zero():
+            quotient.increment()
+        return quotient
+    except BaseException:
+        quotient.close()
+        raise
+    finally:
+        remainder.close()
+
+
+def coarse_depth(width, dimension, maximum_rank):
+    current = Count(width)
+    threshold = Count.literal(dimension)
+    result = Count.literal(0)
+    try:
+        while compare(current, threshold) >= 0:
+            current.divide_small(dimension)
+            if maximum_rank > 1:
+                current.multiply_small(maximum_rank)
+            result.increment()
+        return result
+    except BaseException:
+        result.close()
+        raise
+    finally:
+        current.close()
+        threshold.close()
+
+
+FIELDS = ("precision", "selected", "left", "right", "coefficients", "outer_rows", "residue", "zero",
+          "d", "K", "G", "H", "depth", "q0", "qF", "qB", "Q0", "delta",
+          "input_bits", "work_bits", "gaussians", "prefixes", "original_rows",
+          "padded_rows", "stock", "row_bits", "core_width", "core_front", "core_back")
+
+
+class RootPlan:
+    def __init__(self, dimension, maximum_rank, level_divisor, guard_exponent=210000):
+        need(type(dimension) is int and 2 <= dimension <= 73 and
+             type(maximum_rank) is int and 0 < maximum_rank < dimension and
+             type(level_divisor) is int and level_divisor > 1 and
+             type(guard_exponent) is int and guard_exponent >= 0, "fixed root construction constants")
+        self.dimension, self.maximum_rank, self.level_divisor = dimension, maximum_rank, level_divisor
+        self.guard_exponent = guard_exponent
+        self.roles = {name: Tape() for name in FIELDS}
+        self.pool = ScratchPool(256)
+        self.scope = OuterScope(self.pool)
+        self.fast = False
+        self.closed = True
+
+    def count(self, name):
+        value = object.__new__(Count)
+        value.tape = self.roles[name]
+        return value
+
+    def clear(self):
+        need(not self.pool.live, "closed root planning scratch")
+        for tape in self.roles.values():
+            tape.clear()
+        self.closed = True
+
+    def compute(self, precision, selected, left, right, coefficients, outer_rows, residue):
+        need(self.closed and not self.pool.live, "closed root planning entry")
+        self.clear()
+        self.closed = False
+        inputs = dict(precision=precision, selected=selected, left=left, right=right,
+                      coefficients=coefficients, outer_rows=outer_rows, residue=residue)
+        need(all(isinstance(v, Count) for v in inputs.values()), "encoded root inputs")
+        for name, value in inputs.items():
+            copy_symbols(value.tape, self.roles[name])
+        owned = []  # A fixed number of compiled expression results, independent of input widths.
+
+        def keep(value):
+            owned.append(value)
+            return value
+
+        def literal(value):
+            return keep(Count.literal(value))
+
+        def plus(*values, constant=0):
+            result = literal(constant)
+            for value in values:
+                result.add(value)
+            return result
+
+        def times(a, b):
+            return keep(Count.product(a, b))
+
+        def scaled(value, constant):
+            if constant == 0:
+                return literal(0)
+            result = keep(Count(value))
+            if constant > 1:
+                result.multiply_small(constant)
+            return result
+
+        def save(name, value):
+            copy_symbols(value.tape, self.roles[name])
+            return value
+
+        try:
+            with sealed_constructors(), self.scope.installed():
+                save("zero", literal(0))
+                two = literal(2)
+                need(compare(precision, two) >= 0, "root precision at least two")
+                positive(coefficients)
+                positive(outer_rows)
+                d = save("d", keep(floor_power(precision, 997, 1000)))
+                need(compare(selected, d) <= 0, "selected width within root domain")
+                K = save("K", keep(floor_power(d, 1, 500)))
+                need(compare(residue, K) < 0, "selected root residue")
+                logarithm = keep(ceil_log2(precision))
+                G = save("G", plus(scaled(logarithm, 4), constant=6))
+                H = save("H", times(d, G))
+                depth = save("depth", keep(coarse_depth(d, self.dimension, self.maximum_rank)))
+                q0 = save("q0", scaled(depth, (self.level_divisor - 1).bit_length()))
+                qF = save("qF", keep(ceil_divide(scaled(H, 2), K)))
+                qB = save("qB", keep(ceil_divide(H, K)))
+                Q0 = save("Q0", plus(q0, qF, qB))
+                delta = save("delta", scaled(d, 1 << self.guard_exponent))
+                save("input_bits", plus(precision, constant=2))
+                work_bits = save("work_bits", plus(precision, scaled(delta, 2), constant=3))
+                active_bits = times(selected, K)
+                addresses = keep(power_two(plus(left, active_bits, right)))
+                save("gaussians", times(times(addresses, coefficients), outer_rows))
+                self.fast = compare(selected, Q0) > 0
+                if self.fast:
+                    save("core_width", keep(subtract(selected, Q0)))
+                    save("core_front", keep(subtract(times(qF, K), scaled(H, 2))))
+                    save("core_back", plus(keep(subtract(times(qB, K), H)), right))
+                    row_axes = times(q0, K)
+                    original_rows = save("original_rows", keep(power_two(row_axes)))
+                    prefix_count = save("prefixes", times(outer_rows, keep(power_two(left))))
+                    stock = literal(1)
+                    repetitions = keep(Counter(depth))
+                    while not repetitions.finished:
+                        stock.multiply_small(self.level_divisor)
+                        repetitions.decrement()
+                    save("stock", stock)
+                    multiples = keep(ceil_divide(original_rows, stock))
+                    save("padded_rows", times(multiples, stock))
+                    rectangle = plus(keep(subtract(active_bits, row_axes)), right)
+                    row_gaussians = times(keep(power_two(rectangle)), coefficients)
+                    save("row_bits", scaled(times(row_gaussians, work_bits), 2))
+                else:
+                    for name in ("core_width", "core_front", "core_back", "row_bits"):
+                        save(name, literal(0))
+                    for name in ("prefixes", "original_rows", "padded_rows", "stock"):
+                        save(name, literal(1))
+        except BaseException:
+            for tape in self.roles.values():
+                tape.clear()
+            raise
+        finally:
+            for value in reversed(owned):
+                value.close()
+            self.pool.empty()
+            self.closed = True
+        return self
diff --git a/research/minimum-root-row-prefix/vendor/root_streams.py b/research/minimum-root-row-prefix/vendor/root_streams.py
new file mode 100644
index 0000000000..213144a6c9
--- /dev/null
+++ b/research/minimum-root-row-prefix/vendor/root_streams.py
@@ -0,0 +1,141 @@
+# SPDX-License-Identifier: Apache-2.0
+"""Complete root phase sweeps and one-time row padding on encoded streams."""
+import cohort
+cohort.monomial_api()
+from cardinal_counts import Count, positive
+from compact_counts import append_bits, copy_bits
+from compact_layout import Layout
+from encoded import compare, subtract
+from grid_boundary import GridDomainError
+from phase_recipe import Recipe
+from records import Tape
+from scratch_pool import ScratchPool
+from session import (OuterScope, borrowed_tape, erase_marker, initialize_marker,
+                     sealed_constructors)
+from signed_phase import scan
+from stream import Counter
+from words import BLANK, LEFT, need
+
+
+class OutputEngine:
+    def __init__(self, slots):
+        self.pool = ScratchPool(slots)
+        self.scope = OuterScope(self.pool)
+        self.output = Tape()
+        for tape in (*self.pool.tapes, self.output):
+            erase_marker(tape)
+        self.closed = True
+
+    def rearm(self):
+        need(self.closed and self.output.read() == BLANK and not self.pool.live, "consumed root stream output")
+        self.output.step(-1)
+        try:
+            need(self.output.read() in (LEFT, BLANK), "root stream origin")
+            if self.output.read() == BLANK:
+                self.output.write(LEFT)
+        finally:
+            self.output.step(1)
+        for tape in self.pool.tapes:
+            initialize_marker(tape)
+        self.closed = False
+
+    def finish(self, failure):
+        self.pool.empty()
+        for tape in self.pool.tapes:
+            erase_marker(tape)
+        self.output.rewind()
+        self.closed = True
+        if failure is not None:
+            self.output.clear()
+            erase_marker(self.output)
+            raise failure
+        return self.output
+
+
+class PhaseSweep(OutputEngine):
+    def __init__(self):
+        super().__init__(96)
+        self.recipe = Recipe(dict(matrix_rows=[1], offset=0, phase=0,
+                                  linear_Z4=[1], quadratic_rows=[0]), ("active",))
+
+    def run(self, payload, left, selected, right, spacing, residue, width, coefficients, outer_rows):
+        source = borrowed_tape(payload)
+        need(source is not self.output, "distinct root phase input")
+        for value in (spacing, width, coefficients, outer_rows):
+            positive(value)
+        self.rearm()
+        active = record_bits = total = plan = current = result = None
+        failure = None
+        with sealed_constructors(), self.scope.installed():
+            try:
+                need(compare(residue, spacing) < 0, "root phase selected residue")
+                active = Count.product(selected, spacing)
+                record_bits = Count.product(width, coefficients)
+                record_bits.multiply_small(2)
+                plan = Layout(("left", "active", "right"), (left, active, right), record_bits)
+                total = Count.product(plan.row_bits, outer_rows)
+                current = self.pool.acquire()
+                source.rewind()
+                copy_bits(source, current, total)
+                need(source.read() == BLANK, "complete root phase packet")
+                current.rewind()
+                result = scan(current, plan, self.recipe, selected, spacing, residue,
+                              width, coefficients, outer_rows, self.pool.acquire)
+                current = None
+                append_bits(result, self.output)
+            except ValueError as error:
+                failure = error
+            finally:
+                source.rewind()
+                for value in (current, result, active, record_bits, total):
+                    if value is not None:
+                        value.close() if isinstance(value, Count) else value.clear()
+                if plan is not None:
+                    plan.close()
+        return self.finish(failure)
+
+
+class RowPadding(OutputEngine):
+    def __init__(self):
+        super().__init__(16)
+
+    def run(self, payload, prefixes, original_rows, padded_rows, row_bits, remove=False):
+        need(type(remove) is bool, "compiled row-padding direction")
+        for value in (prefixes, original_rows, padded_rows, row_bits):
+            positive(value)
+        source = borrowed_tape(payload)
+        need(source is not self.output, "distinct row-padding input")
+        self.rearm()
+        extra = kept_bits = extra_bits = remaining = skipped = None
+        failure = None
+        with sealed_constructors(), self.scope.installed():
+            try:
+                need(compare(original_rows, padded_rows) <= 0, "row padding does not shrink")
+                extra = subtract(padded_rows, original_rows)
+                kept_bits = Count.product(original_rows, row_bits)
+                extra_bits = Count.product(extra, row_bits)
+                remaining = Counter(prefixes)
+                source.rewind()
+                while not remaining.finished:
+                    copy_bits(source, self.output, kept_bits)
+                    skipped = Counter(extra_bits)
+                    while not skipped.finished:
+                        if remove:
+                            if source.read() != 0:
+                                raise GridDomainError("nonzero padded row returned")
+                            source.step(1)
+                        else:
+                            self.output.append(0)
+                        skipped.decrement()
+                    skipped.close()
+                    skipped = None
+                    remaining.decrement()
+                need(source.read() == BLANK, "complete row padding input")
+            except ValueError as error:
+                failure = error
+            finally:
+                source.rewind()
+                for value in (extra, kept_bits, extra_bits, remaining, skipped):
+                    if value is not None:
+                        value.close()
+        return self.finish(failure)
diff --git a/research/minimum-root-row-prefix/verify.py b/research/minimum-root-row-prefix/verify.py
new file mode 100644
index 0000000000..32fad8f397
--- /dev/null
+++ b/research/minimum-root-row-prefix/verify.py
@@ -0,0 +1,199 @@
+#!/usr/bin/env python3
+"""Check exact prefix minima, root contracts and complete finite endpoints.
+
+The layout interpreter uses exact integers, not physical record primitives.
+Ali Romman with substantial OpenAI Codex assistance. Apache-2.0.
+"""
+import ast
+import hashlib
+import itertools
+import json
+from math import isqrt, prod
+from pathlib import Path
+import random
+import sys
+
+sys.path.insert(0,str(Path(__file__).resolve().parent))
+from reserve import PrefixCompiler, depth, floor_root, need
+ROOT=Path(__file__).resolve().parent
+REPO=ROOT.parents[1]
+
+
+def authenticate():
+    sources=json.loads((ROOT/'SOURCES.json').read_text())
+    inputs=[x for x in sources['files'] if x['usage']=='input']
+    for row in inputs:
+        path=REPO/row['path']
+        need(path.is_file() and hashlib.sha256(path.read_bytes()).hexdigest()==row['sha256'],'source hash: '+row['path'])
+    return len(inputs)
+
+
+def source_consumers():
+    inventory=json.loads((ROOT/'CONSUMER-INVENTORY.json').read_text())
+    tokens=('q0','depth','stock','padded_rows','original_rows')
+    production={};test_files=0
+    for row in inventory:
+        text=(REPO/row['path']).read_text()
+        need(hashlib.sha256(text.encode()).hexdigest()==row['sha256'],'consumer inventory hash')
+        lexical=[t for t in tokens if t in text]
+        need(lexical==row['consumer_tokens'],'lexical inventory')
+        tree=ast.parse(text)
+        references=sorted({node.value for node in ast.walk(tree) if isinstance(node,ast.Constant) and isinstance(node.value,str) and node.value in tokens})
+        name=Path(row['path']).name
+        if name.startswith('check_'):
+            test_files+=1
+        elif references:
+            production[name]=references
+    need(set(production)=={'root_plan.py','root_layer.py'},'complete production descriptor consumers')
+    plan=ast.parse((ROOT/'vendor/root_plan.py').read_text())
+    cls=next(n for n in plan.body if isinstance(n,ast.ClassDef) and n.name=='RootPlan')
+    compute=ast.unparse(next(n for n in cls.body if isinstance(n,ast.FunctionDef) and n.name=='compute'))
+    expected=["d = save('d', keep(floor_power(precision, 997, 1000)))", "K = save('K', keep(floor_power(d, 1, 500)))", "G = save('G', plus(scaled(logarithm, 4), constant=6))", "H = save('H', times(d, G))", "row_axes = times(q0, K)", "original_rows = save('original_rows', keep(power_two(row_axes)))", "multiples = keep(ceil_divide(original_rows, stock))", "save('padded_rows', times(multiples, stock))"]
+    for statement in expected:need(statement in compute,'source formula: '+statement)
+    layer=(ROOT/'vendor/root_layer.py').read_text()
+    streams=(ROOT/'vendor/root_streams.py').read_text()
+    machine=(ROOT/'vendor/machine.py').read_text()
+    need('rows="padded_rows"' in layer, 'machine receives padded rows')
+    need('def run(self, payload, prefixes, original_rows, padded_rows, row_bits, remove=False):' in streams, 'complete padding parameter boundary')
+    need('divide(' in machine and 'unused' in machine, 'machine row quotient retained')
+    return {'source_python_files':len(inventory),'test_files':test_files,'production_literal_consumers':production,'bound_plan_formulas':len(expected)}
+
+
+def finite_minima():
+    cases=0;relaxed=0;all_depths=0
+    for m,r,threshold in [(3,2,3),(3,2,7),(3,2,13),(73,48,73),(73,48,101)]:
+        ranks=(1,2) if m==3 else (1,2,3,4,5,7,8,48)
+        table=[0]*2049
+        for w in range(threshold,len(table)):
+            table[w]=1+max(table[x*(w//m)] for x in ranks)
+        for w,d in enumerate(table):
+            need(d==depth(w,threshold,m,r),'all-child depth')
+            all_depths+=1
+        for f,k in itertools.product((2,3,7,16,17),(1,2,3,5)):
+            compiler=PrefixCompiler(f,threshold,m,r)
+            for remaining in range(1,201):
+                got=compiler.compile(remaining,k)
+                first=None
+                for q0 in range(remaining):
+                    stock=f**table[remaining-q0]
+                    rows=1<<(k*q0)
+                    padded=((rows+stock-1)//stock)*stock
+                    if padded < 2*rows:
+                        first=q0
+                        break
+                need(got['q0']==first,'direct padded-volume minimum')
+                stock=f**got['depth'];rows=1<<(k*first)
+                if stock>rows:relaxed+=1
+                cases+=1
+    need(relaxed>0,'strict volume improvement over rows>=stock')
+    return {'minimum_cases':cases,'all_child_depth_entries':all_depths,'cases_with_rows_below_stock':relaxed}
+
+
+def apply_axis(values,bit,fields):
+    out=values.copy();mask=1<<bit
+    addresses=len(values)//fields
+    for index in range(addresses):
+        if index & mask:continue
+        for field in range(fields):
+            a=values[index*fields+field];b=values[(index|mask)*fields+field]
+            out[index*fields+field]=a+2*b
+            out[(index|mask)*fields+field]=3*a+5*b
+    return out
+
+
+def layout_checks():
+    rng=random.Random(66151);cases=0;components=0;added=0;reject=0
+    for selected,k,qF,qB,right,fields,prefixes in [(5,1,1,1,1,2,3),(6,1,1,1,0,3,2),(4,2,1,1,1,2,2),(5,2,1,1,0,1,2),(4,1,0,1,1,2,2)]:
+      for divisor in (3,5,7):
+        remaining=selected-qF-qB
+        compiler=PrefixCompiler(divisor,3,3,2)
+        plan=compiler.compile(remaining,k);q0=plan['q0'];core=remaining-q0
+        R=1<<(k*q0);S=divisor**plan['depth'];P=((R+S-1)//S)*S
+        need(P<2*R and P%S==0,'small layout admission')
+        per_row=(1<<((selected-q0)*k+right))*fields
+        for residue in range(k):
+            original=[rng.randrange(-11,12) for _ in range(prefixes*R*per_row)]
+            expected=[];actual=[]
+            block=R*per_row
+            for pre in range(prefixes):
+                v=original[pre*block:(pre+1)*block]
+                direct=v.copy()
+                for axis in range(selected):direct=apply_axis(direct,right+residue+axis*k,fields)
+                expected.extend(direct)
+                a=q0+qF
+                for axis in list(range(selected-a,selected))+list(range(qB)):
+                    v=apply_axis(v,right+residue+axis*k,fields)
+                v += [0]*((P-R)*per_row)
+                # Each complete row endpoint acts on the core and preserves its row index.
+                completed=[]
+                for row in range(P):
+                    piece=v[row*per_row:(row+1)*per_row]
+                    for axis in range(qB,qB+core):piece=apply_axis(piece,right+residue+axis*k,fields)
+                    completed.extend(piece)
+                need(all(x==0 for x in completed[R*per_row:]),'zero padding return')
+                actual.extend(completed[:R*per_row])
+                if P>R:
+                    bad=completed.copy();bad[-1]=1
+                    need(any(x!=0 for x in bad[R*per_row:]),'dirty padding control');reject+=1
+            need(actual==expected,'complete tensor and layout endpoint')
+            need(original!=expected,'nontrivial dirty endpoint')
+            cases+=1;components+=len(original);added+=prefixes*(P-R)*per_row
+    need(added>0 and reject>0,'nontrivial padding coverage')
+    return {'complete_layouts':cases,'dirty_components':components,'added_zero_components':added,'nonzero_padding_controls':reject}
+
+
+def tail_theorem():
+    # For u=floor(log2 p), v=floor(997u/500000), v>=27 once u>=14000.
+    # 2^v > 5284*(ceil(500000*(v+1)/997)+1) holds from v=27.
+    v=27
+    rhs=5284*((500000*(v+1)+996)//997+1)
+    need((1<<v)>rhs,'one-axis base')
+    # One increment in v increases the ceiling by at most 502.
+    increment=5284*502
+    need(rhs>=increment,'one-axis induction')
+    for v in range(27,256):
+        bound=5284*((500000*(v+1)+996)//997+1)
+        need((1<<v)>bound,'tail control')
+    # r^2/m^2 < 1/2 gives D0(d)<=2 ceil(log2 d).
+    need(2*48*48<73*73,'two-level halving')
+    return {'precision_cutoff':'2^14000','base_v':27,'base_rhs':rhs,'base_power':1<<27,'max_rhs_increment':increment,'tail_controls':229}
+
+
+def production():
+    F=14336*(1<<1296)*prod((1<<(2*j))-1 for j in range(1,37))
+    need((F-1).bit_length()==2642,'actual fixed divisor bits')
+    d=isqrt(1<<16949)
+    need(d*d <= 1<<16949 < (d+1)*(d+1),'production floor')
+    K=floor_root(d,500);T=floor_root(d-1,1000)+1;G=34006;H=d*G
+    need(K**500<=d<(K+1)**500,'actual spacing')
+    qF=(2*H+K-1)//K;qB=(H+K-1)//K
+    old=2642*depth(d,73)
+    compiler=PrefixCompiler(F,T)
+    rows=[]
+    for name,selected in [('full',d),('old_lambda45',qF+qB+old+73*45),('old_lambda72',qF+qB+old+73*72)]:
+        need(qF+qB<selected<=d and K>3*G,'production fast domain')
+        plan=compiler.compile(selected-qF-qB,K)
+        core=selected-qF-qB-plan['q0']
+        threshold=T; inverse_depth=0
+        while threshold<=core:
+            inverse_depth+=1
+            threshold=73*((threshold+47)//48)
+        need(inverse_depth==plan['depth'], 'independent inverse depth at production core')
+        front=qF*K-2*H;back=qB*K-H
+        need(front+3*H+core*K+back==(selected-plan['q0'])*K,'whole root address identity')
+        need(0<=front<K and 0<=back<K,'guard residues')
+        need(plan['q0']<=old,'old planner dominates new prefix')
+        row={'case':name,'old_prefix':old,'old_stock_depth':depth(d,73),'new_core_bit_length':core.bit_length(),**plan}
+        if core.bit_length()<64:row['new_core_width']=core
+        rows.append(row)
+    need(rows[0]['q0']==293 and rows[1]['q0']==rows[2]['q0']==1,'production minima')
+    return {'precision':'2^8500','spacing':K,'threshold':T,'divisor_ceil_log2':2642,'plans':rows}
+
+
+def main():
+    result={'status':'PASS_MINIMUM_ROOT_ROW_PREFIX','authenticated_inputs':authenticate(),'consumer_audit':source_consumers(),'finite_minima':finite_minima(),'layout':layout_checks(),'one_axis_tail':tail_theorem(),'production':production(),'limits':['Reference integer compiler and written encoded algorithm; no installed production Count frontend','Inherited complete recursive/native/physical endpoints','No matched QQ16 comparison or new kappa']}
+    saved=ROOT/'RESULT.json'
+    if saved.exists():need(json.loads(saved.read_text())==result,'saved result mismatch')
+    print(json.dumps(result,indent=2,sort_keys=True))
+
+if __name__=='__main__':main()