mkDictFunTy :: [TyVar] -> ThetaType -> Class -> [Type] -> Type
mkDictFunTy tvs theta clas tys
 = mkSigmaTy tvs theta (mkClassPred clas tys)
mkDictFunTy :: [TyVar] -> ThetaType -> Class -> [Type] -> Type
mkDictFunTy tvs theta clas tys
 = mkSigmaTy tvs theta (mkClassPred clas tys)
mkDictFunTy tvs theta clas tys
 = mkSigmaTy tvs theta (mkClassPred clas tys)