Re: [Haskell-cafe] Monad proof

2008-04-14 Thread harke
Here's part of a pencil-and-paper proof of laws for a state monad. Before doing so, I've got a question of my own about the *other* laws: Is there a place where somebody has explicitly written the laws that non-proper morphisms of commonly used monads? Back to the original question... Beware.

Re: [Haskell-cafe] Monad proof

2008-04-14 Thread Derek Elkins
On Mon, 2008-04-14 at 16:52 -0700, [EMAIL PROTECTED] wrote: Here's part of a pencil-and-paper proof of laws for a state monad. Before doing so, I've got a question of my own about the *other* laws: Is there a place where somebody has explicitly written the laws that non-proper morphisms of

[Haskell-cafe] Monad proof

2008-04-11 Thread Rafael C. de Almeida
Hello, I was studying Monads and I was trying to think about new Monads I could define. So, a question poped into my mind: how is proof regarding the 3 Monad laws handled? I know that, aside from testing all the possible values (and there can be a lot of them), there's no general way to

Re: [Haskell-cafe] Monad proof

2008-04-11 Thread Rodrigo Geraldo
Did you see this? http://okmij.org/ftp/Computation/proving-monad-laws.txt []'s Rodrigo Geraldo Ribeiro. PhD student - UFMG On Fri, Apr 11, 2008 at 2:35 PM, Rafael C. de Almeida [EMAIL PROTECTED] wrote: Hello, I was studying Monads and I was trying to think about new Monads I could

Re: [Haskell-cafe] Monad proof

2008-04-11 Thread Ryan Ingram
I really like Chuan-Kai Lin's Unimo paper; in it he talks about defining a monad in terms of defining the behavior of its effects: http://web.cecs.pdx.edu/~cklin/papers/unimo-143.pdf Prompt is based on the same idea, with one small difference. While it's possible to write observation