proposition: Fact size_odd_poly_exp2n n p : (size p <= 2 ^ n.+1 -> size (odd_poly p) <= 2 ^ n)%N.
proof: Proof. move=> Hs; apply: leq_trans (size_odd_poly _) _. by rewrite leq_half_double (leq_trans Hs) // -mul2n -expnS. Qed.
imports: mathcomp(all_ssreflect all_algebra ssrnum) digitn