proposition: Lemma umfilt_mem0X p f k v : (k, v) \In f -> um_filter p f = Unit -> ~ p (k, v).
proof: Proof. by move=>H /umfilt_mem0/(_ _ _ H)/negP. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)