proposition: Lemma domPtUnO A h x (v : A) (f : partition (x :-> v) h) : dom (untag f) =i [pred y | valid (untag f) & (x == y) || (y \in dom h)].
proof: Proof. by rewrite partitionE; apply: domPtUn. Qed.
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat eqtype seq path) pcm(options axioms finmap) pcm(pcm unionmap)