[snip]
I think that this is the more helpful way to look at it, personally. Also, in case you're not aware, it might might be helpful to know that the postfix underscore is part of a naming convention[1], so when you see that (particularly with respect to monads), you can expect (but are not guaranteed!) similar behavior. The postfix capital 'M' is also part of a convention, as noted in the link.
[1] http://haskell.org/ghc/docs/latest/html/libraries/base/Control-Monad.html#g:...
Michael
Thanks everybody... I have to say that I am in full agreement with a post a few days back that said that understanding the type system not only in how the signatures are written but how they interact with eachother is absolutely key to getting your head around Haskell. My daily blub language is currently PHP and the company I am at seem about to cave in and let me use Erlang too which would be really nice BUT Haskell is the place I want to go... having been a software developer for twenty five years, I have personally made most of the mistakes Haskell helps to avoid! LMAO :) Thanks everybody.