-mkTupNameStr 2 = SLIT("(,)") -- not strictly necessary
-mkTupNameStr 3 = SLIT("(,,)") -- ditto
-mkTupNameStr 4 = SLIT("(,,,)") -- ditto
+mkTupNameStr 2 = _PK_ "(,)" -- not strictly necessary
+mkTupNameStr 3 = _PK_ "(,,)" -- ditto
+mkTupNameStr 4 = _PK_ "(,,,)" -- ditto