+ Evidence variables
+%* *
+%************************************************************************
+
+\begin{code}
+isEvVar :: Var -> Bool
+isEvVar var = isPredTy (varType var)
+
+isDictId :: Id -> Bool
+isDictId id = isDictTy (idType id)
+
+evVarPred :: EvVar -> PredType
+evVarPred var
+ = case splitPredTy_maybe (varType var) of
+ Just pred -> pred
+ Nothing -> pprPanic "evVarPred" (ppr var <+> ppr (varType var))
+\end{code}
+
+%************************************************************************
+%* *