Typed Racket uses macro expansion to translate its typed surface language into a typed core language, and then typechecks the core language. Our approach uses

Typed Racket uses macro expansion to translate its typed surface language into a typed core language, and then typechecks the core language. Our approach uses macro expansion to typecheck the surface language and translates it into an untyped core language. The two approaches should be considered alternative tools in a programmer's toolbox.