proposition: Fact in_alg_is_rmorphism : multiplicative (in_alg_loc A).
proof: Proof. by split=> [x y|] /=; rewrite ?scale1r // -scalerAl mul1r scalerA. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)