proposition: Lemma umfoldlPtUn a k v z0 d f : valid (pts k v \+ f) -> all (ord k) (dom f) -> um_foldl a z0 d (pts k v \+ f) = um_foldl a (a z0 k v) d f.
proof: Proof. by move=>W H; rewrite /um_foldl /= 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)