proposition: Lemma freeE f k : free f k = to (UM.free (from f) k).
proof: Proof. by case: f=>[|f H] //; rewrite heapE. Qed.
imports: Coq(ssreflect ssrbool ssrfun Eqdep) mathcomp(ssrnat eqtype seq path) pcm(options axioms finmap) pcm(pcm unionmap)