Definition iso3 := [set p | is_iso3b p].

(* Specifications: *)
Lemma is_iso3P : forall p, reflect (is_iso3 p) (p \in iso3).
Lemma group_set_iso3 : group_set iso3.
Canonical iso_group3 := Group group_set_iso3.
Lemma group_set_diso3 : group_set  dir_iso3.
Canonical diso_group3 := Group group_set_diso3.
Lemma gen_diso3 :  dir_iso3 = <<[set r05; r14]>>.
Notation col_cubes := {ffun cube -> colors}.