fact: Definition act_g (sc : col_cubes) (p : {perm cube}) : col_cubes := [ffun z => sc (p^-1 z)].
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(choice fintype tuple finfun bigop finset fingroup) mathcomp(action perm primitive_action)