Doc fixes and typos in coerce_to_context

Author: Jake Moss

src/flint/flint_base/flint_base.pyx

@@ -987,7 +987,7 @@ cdef class flint_mpoly(flint_elem):
             mapping = ctx.infer_generator_mapping(other_ctx)
         else:
             mapping = {
-                ctx.variable_to_index(k): ctx.variable_to_index(v)
+                ctx.variable_to_index(k): other_ctx.variable_to_index(v)
                 for k, v in mapping.items()
             }
 
@@ -996,7 +996,7 @@ cdef class flint_mpoly(flint_elem):
             if c_mapping is NULL:
                 raise MemoryError("malloc returned a null pointer")
 
-            for i in range(self.ctx.nvars()):
+            for i in range(ctx.nvars()):
                 c_mapping[i] = <slong>-1
 
             for k, v in mapping.items():

src/flint/types/fmpq_mpoly.pyx

@@ -702,9 +702,11 @@ cdef class fmpq_mpoly(flint_mpoly):
         Return a dictionary of variable name to degree.
 
             >>> ctx = fmpq_mpoly_ctx.get(('x', 4), 'lex')
-            >>> p = ctx.from_dict({(1, 0, 0, 0): 1, (0, 2, 0, 0): 2, (0, 0, 3, 0): 3})
+            >>> p = sum(x**i for i, x in enumerate(ctx.gens()))
+            >>> p
+            x1 + x2^2 + x3^3 + 1
             >>> p.degrees()
-            (1, 2, 3, 0)
+            (0, 1, 2, 3)
         """
         cdef:
             slong nvars = self.ctx.nvars()

src/flint/types/fmpz_mod_mpoly.pyx

@@ -707,9 +707,11 @@ cdef class fmpz_mod_mpoly(flint_mpoly):
         Return a dictionary of variable name to degree.
 
             >>> ctx = fmpz_mod_mpoly_ctx.get(('x', 4), 11, 'lex')
-            >>> p = ctx.from_dict({(1, 0, 0, 0): 1, (0, 2, 0, 0): 2, (0, 0, 3, 0): 3})
+            >>> p = sum(x**i for i, x in enumerate(ctx.gens()))
+            >>> p
+            x1 + x2^2 + x3^3 + 1
             >>> p.degrees()
-            (1, 2, 3, 0)
+            (0, 1, 2, 3)
         """
         cdef:
             slong nvars = self.ctx.nvars()

src/flint/types/fmpz_mpoly.pyx

@@ -692,7 +692,7 @@ cdef class fmpz_mpoly(flint_mpoly):
         Return a tuple of degrees.
 
             >>> ctx = fmpz_mpoly_ctx.get(('x', 4), 'lex')
-            >>> p = sum(x**(2 * i) for i, x in enumerate(ctx.gens()))
+            >>> p = sum(x**i for i, x in enumerate(ctx.gens()))
             >>> p
             x1 + x2^2 + x3^3 + 1
             >>> p.degrees()
@@ -961,10 +961,6 @@ cdef class fmpz_mpoly(flint_mpoly):
             (<fmpz_mpoly_ctx>ctx).val
         )
 
-        if not fmpz_mpoly_is_canonical(res.val, res.ctx.val):
-            fmpz_mpoly_sort_terms(res.val, res.ctx.val)
-            fmpz_mpoly_combine_like_terms(res.val, res.ctx.val)
-
         return res
 
     def derivative(self, var):

src/flint/types/nmod_mpoly.pyx

@@ -687,9 +687,11 @@ cdef class nmod_mpoly(flint_mpoly):
         Return a dictionary of variable name to degree.
 
             >>> ctx = nmod_mpoly_ctx.get(('x', 4), 11, 'lex')
-            >>> p = ctx.from_dict({(1, 0, 0, 0): 1, (0, 2, 0, 0): 2, (0, 0, 3, 0): 3})
+            >>> p = sum(x**i for i, x in enumerate(ctx.gens()))
+            >>> p
+            x1 + x2^2 + x3^3 + 1
             >>> p.degrees()
-            (1, 2, 3, 0)
+            (0, 1, 2, 3)
         """
         cdef:
             slong nvars = self.ctx.nvars()