| ty, _ -> raise (Type_mismatch (name, ty))
let opt_binding_some (n, (ty, v)) = (n, (OptType ty, OptValue (Some v)))
-let opt_binding_none (n, (ty, v)) = (n, (OptType ty, OptValue None))
+let opt_binding_none (n, (ty, _v)) = (n, (OptType ty, OptValue None))
let opt_binding_of_name (n, ty) = (n, (OptType ty, OptValue None))
let list_binding_of_name (n, ty) = (n, (ListType ty, ListValue []))
let opt_declaration (n, ty) = (n, OptType ty)