+\subsection[TysWiredIn-tuples]{The tuple types}
+%* *
+%************************************************************************
+
+\begin{code}
+tupleTyCon :: Arity -> TyCon
+tupleTyCon arity
+ = tycon
+ where
+ tycon = mkTupleTyCon uniq name arity
+ uniq = mkTupleTyConUnique arity
+ name = mkWiredInTyConName uniq mod_name (mkTupNameStr arity) tycon
+ mod_name | arity == 0 = pREL_BASE
+ | otherwise = pREL_TUP
+
+tupleCon :: Arity -> Id
+tupleCon arity
+ = tuple_con
+ where
+ tuple_con = mkTupleCon arity name ty
+ uniq = mkTupleDataConUnique arity
+ name = mkWiredInIdName uniq mod_name (mkTupNameStr arity) tuple_con
+ mod_name | arity == 0 = pREL_BASE
+ | otherwise = pREL_TUP
+ ty = mkSigmaTy tyvars [] (mkFunTys tyvar_tys (applyTyCon tycon tyvar_tys))
+ tyvars = take arity alphaTyVars
+ tyvar_tys = mkTyVarTys tyvars
+ tycon = tupleTyCon arity
+
+unitTyCon = tupleTyCon 0
+pairTyCon = tupleTyCon 2
+
+unitDataCon = tupleCon 0
+pairDataCon = tupleCon 2
+\end{code}
+
+
+%************************************************************************
+%* *