[Haskell-cafe] Laws in category theory..

Ron de Bruijn rondebruijn at yahoo.com
Sat Jun 19 05:30:02 EDT 2004

I have been thinking about the following laws of a
monad. o is composition. 

# associative law of a monad 
mu o (mu o T) == mu o (T o mu)

The notation: Tmu, that's the same as T o mu, right?

How do I relate this to 
x*(y*z) == (x*y)*z ?

# the identity law of a monad 
mu o (T o eta) =={id}_\mathcal{C}= mu o (eta o T)

I also don't understand why I can't create the
following law out of the assocaitive law:
(mu o T) ==  (T o mu)
, bacause the first part of the expression is the

Please, enlighten me :)

Regards, Ron

Do you Yahoo!?
New and Improved Yahoo! Mail - 100MB free storage!

More information about the Haskell-Cafe mailing list