-implementation module main
-
-import Data.GenDefault
-import StdEnv
-
-import Sub
-
-gDefault{|Expr|} = Lit 0
-
-eval :: Expr -> Int
-eval (Lit i) = i
-eval (e1 +. e2) = eval e1 + eval e2
-eval x = evalSub x
-
-pprint :: Expr -> String
-pprint (Lit i) = toString i
-pprint (e1 +. e2) = pprint e1 +++ " + " +++ pprint e2
-pprint x = pprintSub x
-
-Start = pprint (Lit 5 -. Lit 6)