proposition: Lemma issymP p : reflect (forall s, msym s p = p) (p \is symmetric).
proof: Proof. apply: (iffP forallP)=> /= h s; last by rewrite h. by rewrite (eqP (h s)). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype tuple finfun bigop finset binomial) mathcomp(order fingroup perm ssralg zmodp poly ssrint) mathcomp(matrix vector) mathcomp(bigenough) ssrcomplements freeg