proposition: Lemma ummonoUnR f1 f2 : valid (f1 \+ f2) -> um_mono (f1 \+ f2) -> um_mono f2.
proof: Proof. by rewrite joinC; apply: ummonoUnL. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)