On Sep 17, 2009, at 20:17 , xu zhang wrote:
case op of
And -> let a = 4
Or -> let a = 3
Implies -> let a = 2
Equiv -> let a = 1
"let" isn't an assignment command, it's a scoping command. That is,
> let a = 3 in ...
is equivalent to something lik
Am Freitag 18 September 2009 02:17:22 schrieb xu zhang:
> showMinProp :: Int -> Prop -> String
> showMinProp preNo (BinOp op p q) =
> case op of
> And -> let a = 4
> Or -> let a = 3
> Implies -> let a = 2
> Equiv -> let a = 1
> if (a > preNo)
>
Hi, I am trying to get the function showMinProp to return String, but I
always get an error of parse error (possibly incorrect indentation)
Who can help with this? any idea?
Thank u in advance!
data Prop
= Var String
| Negation Prop
| BinOp Op Prop Prop
data Op = And | Or | Implies | Equiv
