Re: [boost] Interval Library and comparison operators

From: Joel Young (jdy_at_[hidden])
Date: 2002-09-05 10:48:54

From: Guillaume Melquiond <gmelquio_at_[hidden]>
> 4. Then came Joel Young and his 13 relational operators.
> 
> I find this way of describing relations really nice; but unless I'm
> missing the point, I don't see how it solves the previous problems. Or was
> it meant to completely remove all the comparison operators?

Please look at this webpage:

http://www.cs.brown.edu/people/jdy/intervals/

I give three different partitionings of the interval-interval relation
space.  There are many more.  I may add to this as time goes on because
it is fun. :-)

What I am trying to say is that using the geometric technique gives a
clean way of visualizing and defining your boolean comparison relations.
If you need <, == and define the others in terms of these then using
this technique is easy.  (Look at the second two figures on the page).

>= is equivalent to {>, =} is equivalent to not(<) and so on.

I created these diagrams and page very quickly so I apologize for any
typos.

Joel