proposition: Lemma lift_set_eq_compat {U} (s1 s2 : set U) : s1 <--> s2 -> lift s1 <--> lift s2.
proof: Proof. firstorder. Qed.
imports: mathcomp.ssreflect.ssreflect Classes.RelationClasses Classes.Morphisms List Tactics mathcomp(ssrfun ssrbool ssrnat seq)