Thanks Ryan, I'm slowly becoming aware of the effects of Monomorphism. I'll look
again at Neil Mitchell's blog post.

I guess it's the same thing when I try:

> let a = 1
> a + 1.0

I'm taking the "mono" as a clue that the type inferencing will complete after
each ghci carriage return; once only. In this example when "a" is set, it is
to an Integer. One might imagine ghci could wait until I use "a" somewhere, but
that's not how things are.