[Haskell-cafe] Short circuiting and the Maybe monad

[Dan Piponi]

On Wed, May 14, 2008 at 12:03 PM, Andrew Coppin
<andrewcoppin at btinternet.com> 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

Anyway, I worked through an elementary example of this with usable
source code here:
http://sigfpe.blogspot.com/2006/11/variable-substitution-gives.html
--
Dan