Re: [Haskell-cafe] A question about "monad laws"

IOn Feb 11, 2008 9:46 AM, Miguel Mitrofanov wrote:

It's well known that "ListT m" monad violates this law in general (though it satisfies it for some particular monads m). For example,

I went through this example in quite a bit of detail a while ago and wrote it up here: http://sigfpe.blogspot.com/2006/11/why-isnt-listt-monad.html . I tried to show not just why the monad laws fails to hold for ListT [], but also show how it almost holds. -- Dan