proposition: Fact Zp_mul_comm : forall x y, x ⊗ y = y ⊗ x.
proof: Proof. intros (x & ?) (y & ?); apply Zp_inj; simpl. f_equal; ring. Qed.
imports: Arith Lia ZArith List Permutation Eqdep_dec Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list gcd prime binomial sums php) Undecidability.H10.ArithLibs(matrix)