proposition: Lemma bigdprodWY I (r : seq I) P F G : \big[dprod/1]_(i <- r | P i) F i = G -> << \bigcup_(i <- r | P i) F i >> = G.
proof: Proof. by move/bigdprodWcp; apply: bigcprodWY. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq div) mathcomp(choice fintype bigop finset fingroup morphism) mathcomp(quotient action)