proposition: Lemma big_id_idem_AC I (r : seq I) P F : \big[op/x]_(i <- r | P i) op (F i) x = \big[op/x]_(i <- r | P i) F i.
proof: Proof. by rewrite big_split_idem big_const_idem ?big_id_idem. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq path) mathcomp(div fintype tuple finfun)