proposition: Lemma umfoldrPtUn a k v z0 d f : valid (pts k v \+ f) -> all (ord k) (dom f) -> um_foldr a z0 d (pts k v \+ f) = a k v (um_foldr a z0 d f).
proof: Proof. by move=>W H; rewrite /um_foldr W (validR W) assocsPtUn. Qed.
imports: Coq(ssreflect ssrbool ssrfun) mathcomp(ssrnat eqtype seq path bigop) pcm(options prelude finmap seqperm pred seqext) pcm(pcm morphism)