proposition: Lemma fgaddC : commutative fgadd.
proof: Proof. by move=> x y; apply/malgP=> k; rewrite !fgaddE addrC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap