+mkArityMsg :: Id -> Message
+mkArityMsg binder
+ = vcat [hsep [ptext (sLit "Demand type has "),
+ ppr (dmdTypeDepth dmd_ty),
+ ptext (sLit " arguments, rhs has "),
+ ppr (idArity binder),
+ ptext (sLit "arguments, "),
+ ppr binder],
+ hsep [ptext (sLit "Binder's strictness signature:"), ppr dmd_ty]
+
+ ]
+ where (StrictSig dmd_ty) = idNewStrictness binder
+