Set difference (or nearest approximation)
Daniel Vainsencher
danielv at tx.technion.ac.il
Wed Dec 12 14:08:26 UTC 2007
In mathematical language, you are expecting a symmetric difference, but
what people in the math dept I learned in usually mean by set difference
is what Squeak seems to be doing. Wikipedia seems to agree [1].
[1] http://en.wikipedia.org/wiki/Complement_%28set_theory%29
Daniel
cdrick wrote:
>
>
> 2007/12/12, cdrick <cdrick65 at gmail.com <mailto:cdrick65 at gmail.com>>:
>
> just playing around:
>
> (#(1 2 3) asSet) difference: (#(1 2 3 4 5) asSet)
> a Set()
>
>
> to be more complete:
>
> #(1 2 9) asSet difference: #(1 3) asSet a Set(2 9)
> #(1 2 3 9) asSet difference: #(1 2 3 4 5) asSet a Set(9)
>
> is it the right definition of set differece ?
> aren't we expecting union minus intersection ?
>
>
> ------------------------------------------------------------------------
>
>
>
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