[Hugs] Hugs doesn't know List Difference operator (\\)

I'm reading some Haskell Tutorial when I arrive at List Difference operator, which is \\. But when I try on Hugs, it responded: ERROR - Undefined variable "\\" -- View this message in context: http://www.nabble.com/Hugs-doesn%27t-know-List-Difference-operator-%28%5C%5C... Sent from the Haskell - Hugs-Bugs mailing list archive at Nabble.com.