Mmmmmmmm......... and then How can I solve this problem? Would you say the solution. Thank you. "Ashley Yakeley" wrote in message news:ashley-7A3E01.22122409012004@sea.gmane.org...

In article , "NamO" wrote:

...

But above source make an error like bellow

Reading file "g:\Haskell\OperationTest.hs": Dependency analysis ERROR "g:\Haskell\OperationTest.hs":8 - Ambiguous variable occurrence "+" *** Could refer to: OperationTest.+ Prelude.+

There's already a definition for (+) imported from the Prelude. When you write "Succ (m + n)" the interpreter doesn't know whether you mean the one you've just defined ("OperationTest.+") or the one imported from the Prelude ("Prelude.+").

-- Ashley Yakeley, Seattle WA

On Sat, 10 Jan 2004 04:28:33 -0800 Ashley Yakeley wrote:

In article , "NamO" wrote:

...

Mmmmmmmm.........

and then How can I solve this problem? Would you say the solution. Thank you.

Either use a different name for your operator, or specify the "+" that you want by writing "OperationTest.+" instead of "+".

You can also hide the Prelude (+), though it is a somewhat useful function. import Prelude hiding ( (+) )