proposition: Lemma fgadd0g : left_id fgzero fgadd.
proof: Proof. by move=> x; apply/malgP=> k; rewrite fgaddE fgzeroE add0r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq path choice finset fintype finfun) mathcomp(tuple bigop ssralg ssrint ssrnum) xfinmap