Thanks for all the answers! Obviously this question including the
suggestions should be in the FAQ.

I understand that all you functional experts thinks this restriction is
obvious, but for me it is more like a bug/misfeature. So this 'misfeature'
should actually be stated for all us who aren't interested how types are
infered in functional programming.

I actually thought there was a simple work-around, but there isn't.

/mattias