darcs patch: Add equating p x y = p x == p y

[kahl at cas.mcmaster.ca]

 > 
 > I would like to propose a new module for functions like this, which are
 > in some sense "purely" functional, that is, they do not involve any data
 > structure at all, just functions.  Other examples would be
 > 
 >     const
 >     id
 >     flip
 >     (.)
 >     ($)
 >     ($!)
 > 
 > Any suggestions for a good name for such a module?  Data.Function does
 > not sound right to my ears.

It does sound right to my ears,
and I thought of it before I read to the last paragraph.

In my lectures, I use the example of shows versus show
to demonstrate that functions can be a more efficient datatype
than more conventional datatypes like lists...


Wolfram