# gcd 0 0 = 0

**Marc van Dongen
**
dongen@cs.ucc.ie

*Tue, 18 Dec 2001 17:02:36 +0000*

Lars Henrik Mathiesen (thorinn@diku.dk) wrote:
:* > Alan Bawden (Alan@LCS.MIT.EDU) wrote:
*:* > : Indeed, that's a nice way of putting it. How about if the report just
*:* > : says:
*:* > :
*:* > : In order to make the non-negative integers into a lattice under `gcd'
*:* > : and `lcm', we define `gcd 0 0 = 0'.
*
[snip]
:* This is exactly what you get if you plug the relation 'divides' on the
*:* non-negative integers into the definition of meet in a lattice. So
*:* this formulation is no more or less complex to use than the lattice
*:* one --- and people who do know about lattices will probably realize
*:* this pretty fast.
*
I disagree. Alan is talking about adding things to the haskell report.
That document should be accessible to as many people as possible.
I have not yet met anybody who had lattice theory in primary and/or
secondary school. On the other hand I *have* met quite a few of them
who have a pretty good idea about what it means for one number to
divide another.
[snip]
Regards,
Marc van Dongen
--
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