Do not assign "f"

diff --git a/SimpleFT.hs b/SimpleFT.hs
index 7dda161..2f21c72 100644 (file)
--- a/SimpleFT.hs
+++ b/SimpleFT.hs
@@ -5,6 +5,7 @@ module SimpleFT where
 import ParseType
 import Expr
 import Control.Monad.Reader
 import ParseType
 import Expr
 import Control.Monad.Reader

+import Data.List

 
 test = putStrLn . show . freeTheorem . parseType
 
 
 test = putStrLn . show . freeTheorem . parseType
 


@@ -12,7 +13,7 @@ freeTheorem t = flip runReader freeVars $
                        freeTheorem' (typedLeft  (Var "f") (unquantify t))
                                     (typedRight (Var "f") (unquantify t))
                                      t
                        freeTheorem' (typedLeft  (Var "f") (unquantify t))
                                     (typedRight (Var "f") (unquantify t))
                                      t

-freeVars = (map (:"") ['a'..])
+freeVars = map (:"") (delete 'f' ['a'..])

 
 
 freeTheorem' :: TypedExpr -> TypedExpr -> Typ -> Reader [String] BoolExpr
 
 
 freeTheorem' :: TypedExpr -> TypedExpr -> Typ -> Reader [String] BoolExpr