proposition: Fact cfun_mul1 : left_id '1_G cfun_mul.
proof: Proof. by move=> phi; apply: cfun_in_genP => x Gx; rewrite !cfunE cfun1Egen Gx mul1r. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div choice fintype tuple finfun bigop prime order) mathcomp(ssralg poly finset fingroup morphism perm) mathcomp(automorphism quotient finalg action gproduct) mathcomp(zmodp commutator cyclic center pgroup sylow) mathcomp(matrix vector falgebra ssrnum algC algnum) mathcomp(archimedean)