proposition: Lemma divfI x : x != 0 -> injective (fun y => x / y).
proof: Proof. by move/mulfI/inj_comp; apply; apply: invr_inj. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(choice fintype finfun bigop prime binomial)