proposition: Lemma fmorph_eq1 x : (f x == 1) = (x == 1).
proof: Proof. by rewrite -(inj_eq fmorph_inj) rmorph1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)