[FOM] "Mathematician in the street" on AC

Daniel Méhkeri dmehkeri at yahoo.ca
Thu Aug 20 15:01:06 EDT 2009

> I would ask "is the union of a countable number of countable
> sets countable?"

> Of course only a weak version of AC is needed for that,
> but I would be surprised if in the answer to that question
> "a mathematician in the street" would be even aware that
> AC is involved.

I guess there are loads of examples where weaker versions goes by without comment even where care is being taken to point out full AC.

Maybe this can partly be attributed to ignorance, but would the answer really change even if it was made clear that some sort of choice was involved?

(I ask partly because my own bias is to accept Dependent Choices and not full AC. But note that I'm not a mathematician and we aren't in a street.)


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