proposition: Lemma mem_rangeP x f : reflect (x \In range f) (x \in range f).
proof: Proof. by apply: mem_seqP. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)