proposition: Lemma eq_big_int m n F1 F2 : (forall i, m <= i < n -> F1 i = F2 i) -> \big[op/idx]_(m <= i < n :> int) F1 i = \big[op/idx]_(m <= i < n :> int) F2 i.
proof: Proof. by move=> eqF; apply: congr_big_int. Qed.
imports: mathcomp(all_ssreflect all_algebra) extra_mathcomp