fact: Definition ctree_cons_perm g := let cte c := ctree_cons_e (g c) in palette (cte Color0) (cte Color1) (cte Color2) (cte Color3).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype path fingraph) fourcolor(hypermap geometry color coloring cfmap ctree)