Re: [Haskell-cafe] Short circuiting and the Maybe monad

On Wed, 2008-05-14 at 12:42 -0700, Dan Piponi wrote:

On Wed, May 14, 2008 at 12:03 PM, Andrew Coppin wrote:

...

"It is well-known that trees with substitution form a monad."

Now that's funny. Compare with the first line of this paper: http://citeseer.ist.psu.edu/510658.html

Well, it's well-known. Further, not only do they form a monad, but they are a free monad.