All potential errors now caught into Nothings

1 files changed, 1 insertions, 8 deletions

diff --git a/Term.hs b/Term.hs
index 23fc5c5..dfcf1cf 100644
--- a/Term.hs
+++ b/Term.hs
@@ -2,8 +2,6 @@ module Term (
     Term(..),
     Substitution,
 
-    nullTerm,
-
     alphaEquiv,
     alphaConvert,
     alphaConvertList,
@@ -34,8 +32,7 @@ data Term = TVar { tVar :: Var }
           | TApp { tAppLeft :: Term
                  , tAppRight :: Term }
           | TAbs { tAbsVar :: Term
-                 , tAbsTerm :: Term }
-          | TNull deriving (Ord)
+                 , tAbsTerm :: Term } deriving (Ord)
 
 type Substitution = ( [(Name,Type)], [(Var,Term)] )
 
@@ -54,10 +51,6 @@ instance Eq Term where
 
 
 
-nullTerm :: Term
-nullTerm = TNull
-
-
 alphaEquiv :: Term -> Term -> Bool
 alphaEquiv a b =
     let equiv = \term1 term2 varmap1 varmap2 depth ->