On Fri, 17 Sep 1999 18:09:32 -0700, Ken <tyl### [at] pacbellnet> wrote:

>
>
>Ian Burgmyer wrote:
>> 
>> What's the difference between merge and union?  I noticed that one (I think
>> it was merge) took quite a bit longer then the other.
>> 
>> Thanks!
>> -Ian
>
>  There is a major difference between the two. The union is really not
>a true CSG operation and could be more accurately described as a group
>container.

Interesting distinction you make there.  I'd say union is the true
CSG operation - since it's what we'd generally consider atomic - and 
merge is the imposter; it's able to be synthesized by clever
combination of intersection and inverse.

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