proposition: Lemma sub_class_support A : A \subset class_support A G.
proof: Proof. by rewrite class_supportEr (bigcup_max 1) ?conjsg1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype div path tuple bigop prime finset)