proposition: Lemma fold_ctree_leaf A (vlf vnlf : A) t : (if t is CtreeLeaf _ then vlf else vnlf) = (if ctree_leaf t then vlf else vnlf).
proof: Proof. by case: t. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq) fourcolor(color)