Annoying behaviour of the != operator

[Greg Ewing]

Jordan Rastrick wrote:

> Where are the 'number of situations' where __ne__ cannot be derived
> from __eq__? Is it just the floating point one? I must admit, I've
> missed any others.

The floating point one is just an example, it's not meant
to be the entire justification.

Some others:

* Numeric arrays, where comparisons return an array of
   booleans resulting from applying the comparison to each
   element.

* Computer algebra systems and such like, which return a
   parse tree as a result of evaluating an expression.

-- 
Greg Ewing, Computer Science Dept,
University of Canterbury,	
Christchurch, New Zealand
http://www.cosc.canterbury.ac.nz/~greg