proposition: Lemma umUndef0E : ((undef : union_map_eqType K V) == Unit) = false.
proof: Proof. by apply/eqP/undef0. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)