proposition: Lemma eq_fbigr (A : {fset I}) (P : pred I) (F G : I -> R) : (forall x, x \in A -> P x -> F x = G x) -> \big[op/idx]_(i <- A | P i) F i = \big[op/idx]_(i <- A | P i) G i.
proof: Proof. by apply: eq_fbig_cond. Qed.
imports: HB(structures) mathcomp(ssreflect ssrbool ssrnat eqtype ssrfun seq) mathcomp(choice path finset finfun fintype bigop)