proposition: Lemma invr_out : {in [predC uam], vam =1 id}.
proof: Proof. by move=> u /negbTE/= ->. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq path) mathcomp(choice fintype div tuple finfun bigop ssralg) mathcomp(finalg zmodp matrix vector poly)