proposition: Lemma domPtUnE2 k v1 v2 f : dom (pts k v1 \+ f) = dom (pts k v2 \+ f).
proof: Proof. by apply/domE=>x; rewrite !domPtUn !validPtUn. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)