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| ``Category of Sets, according to MacLane''
by jkauzlar on 2008-06-10 04:28:07 |
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| In his book, p12, he gives the following simple definition:
Set: Objects, all small sets; Arrows, all functions between them.
The article might be clearer to say 'all' morphisms, or even 'all possible' morphisms. Then the one-element sets are terminals because of constant functions. I'm still not clear why the empty set has arrows to all other sets.
Additionally, MacLane qualifies the objects as being 'small' sets. |
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