doc.fix(ast/rewriter/poly_rewriter_params.pyg): typo som-of-monomials -> sum-of-monomials

Author: yxliang01

src/ast/rewriter/poly_rewriter_params.pyg

@@ -1,7 +1,7 @@
 def_module_params(module_name='rewriter',
                   class_name='poly_rewriter_params',
                   export=True,
-                  params=(("som", BOOL, False, "put polynomials in som-of-monomials form"),
+                  params=(("som", BOOL, False, "put polynomials in sum-of-monomials form"),
                           ("som_blowup", UINT, 10, "maximum increase of monomials generated when putting a polynomial in sum-of-monomials normal form"),
                           ("hoist_mul", BOOL, False, "hoist multiplication over summation to minimize number of multiplications"),
                           ("hoist_cmul", BOOL, False, "hoist constant multiplication over summation to minimize number of multiplications"),