proposition: Fact Zp_mult_minus_one x : (∸ Op) ⊗ x = ∸ x.
proof: Proof. 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)