[Haskell-cafe] multiline mode on ghci 8.2.2

I thought I could use the directive ":set +m" to define a function with its signature. Prelude> :set +m Prelude> square :: Num a=>a->a <interactive>:3:1: error: Variable not in scope: square :: a1 -> a1 Instead, I have to type: Prelude> :unset +m Prelude> :{ Prelude| square :: Num a=>a->a Prelude| square = (^2) Prelude| :} Prelude> Any hint ? -- Fabien