Require Export RTopology ProductTopology Homeomorphisms.
(* Ropp_continuous was already proved in RTopology *)

Lemma continuous_2arg_compose : forall {U X Y Z : TopologicalSpace} (f : U -> X) (g : U -> Y) (h : X -> Y -> Z),
continuous f -> continuous g -> continuous_2arg h ->
continuous (fun p => h (f p) (g p)).