diff --git a/research/halo-copy-enumeration/README.md b/research/halo-copy-enumeration/README.md new file mode 100644 index 0000000000..0abc1a3c3d --- /dev/null +++ b/research/halo-copy-enumeration/README.md @@ -0,0 +1,339 @@ +# Gaussian halo input-copy enumeration + +**Scoped all-size combinatorial implication, independent finite verifier, and an +explicit physical-cost boundary. No new κ.** The selected conditional record +remains κ = 0.00302015. On 2026-10-22 the orchestrator replayed the final +algorithm-seam controls and six-input closure under CPython 3.12.13: metadata, +normal and optimized registered runs passed. Finite audit evidence is not +scientific acceptance, a full-tape proof, or selected-result replay. + +This answers Nick Petalas's [#4217 open question](../halo-locality-witness-audit/README.md#open-next-questions), +not his polynomial-locality argument. Its caller is Cinna Davis's +[GAUSSIAN.md lines 177–226](../unconditional-batched-crt/GAUSSIAN.md) and +[HALO.md lines 36–94](../unconditional-batched-crt/HALO.md), retained from #4100. +The new result is the explicit prefix/DFS enumeration, exact copy-volume +identity, independent destination oracle, and separation of non-output setup +from output-sensitive work. It neither repeats the locality factor-two note +nor substitutes exponent arithmetic for a universal algorithm. + +## Definition and quantified result + +Let g >= 1, integer A > 0, L > 4A, 0 <= b < A, and axis periods S_i = n_i L +with n_i >= 2. Coordinates are canonical integers modulo S_i. Here b is a +sufficient input-dependency radius, not a Gaussian conditioning parameter. +For core c, write local coordinates in [0,L). The kept interior is +I = [A,L-A); the lower and upper boundary intervals are B_0 = [0,A) and +B_1 = [L-A,L). All intervals are half-open integer intervals. + +For first boundary axis f and side s, the **output rectangle** is + + R(c,f,s) = I^f × B_s × [0,L)^(g-f-1), translated by cL. + +Its **input rectangle** E(c,f,s) expands every interval by b on both sides, +then reduces coordinates periodically. A canonical source is copied once for +each E containing it, even if it belongs to several destinations. Its full key +is `(destination core tuple, f, s, lifted local tuple, canonical source tuple)`. +The signed local tuple records wrap without losing the destination chart. +Input-copy keys are unique as full keys; source addresses alone need not be. +Returned output keys are canonical global output coordinates, without f or s. + +HALO uses the conservative expansion A. Using b < A is a sufficient tighter +input set for a tensor whose per-axis dependency bandwidth is at most b; it +is contained in the source's A-expanded allocation. Thus the volume upper +bound below also bounds the tighter scheme. This does not silently identify +A and b: a literal A-expanded implementation can use the same interval proof +with b=A (half-open expanded interiors then tile rather than have gaps), but +that variant is outside this verifier's explicitly strict-bandwidth domain. +No polynomial row locality is proved here. The call-site facts bandwidth +=L-b. Because 2b=2, the list has one or two distinct choices. +These are exactly the cores whose expanded full interval contains x_i. +An earlier-axis expanded interior contains x_i exactly when +A-b <= r_i < L-A+b, and its core must be q_i: the expanded interiors are +strictly separated by a positive gap. Precompute these memberships and the +expanded lower/upper face memberships from the same at-most-two candidates. +Every face interval is contained in its expanded full interval, so no face +choice is missed. + +Let prefix[f] be the AND of the interior-membership flags for i