proposition: Lemma exists_eqP f1 f2 : reflect (exists x, f1 x = f2 x) [exists x, f1 x == f2 x].
proof: Proof. exact: 'exists_eqP. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(path div)