proposition: Lemma ifftW (P Q : Prop) : P <=> Q -> (P <-> Q).
proof: Proof. by case. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype finfun perm matrix bigop zmodp mxalgebra) mathcomp(choice poly polydiv mxpoly binomial)