tyClsNamesOfType (PredTy (IParam n ty)) = tyClsNamesOfType ty
tyClsNamesOfType (PredTy (ClassP cl tys)) = unitNameSet (getName cl) `unionNameSets` tyClsNamesOfTypes tys
tyClsNamesOfType (PredTy (EqPred ty1 ty2)) = tyClsNamesOfType ty1 `unionNameSets` tyClsNamesOfType ty2
tyClsNamesOfType (PredTy (IParam n ty)) = tyClsNamesOfType ty
tyClsNamesOfType (PredTy (ClassP cl tys)) = unitNameSet (getName cl) `unionNameSets` tyClsNamesOfTypes tys
tyClsNamesOfType (PredTy (EqPred ty1 ty2)) = tyClsNamesOfType ty1 `unionNameSets` tyClsNamesOfType ty2