FOM: reference of mathematical discourse

[Randall Holmes]

In response to Neil Tennant on "the number of people who went up the hill"

The concept "the number of people that went up the hill" isn't
actually expressible in PA; you would need some set theory for this.

I don't suppose that a constructivist would have much trouble 
with a proof of this in ZF - Power Set - Infinity or in Theory of
Types - Infinity; the best I could do would be to point out that
the proof I would give in ZF or TT or NFU with Infinity would also
be valid in these fragments.

Then I would ask the constructivist about the mathematics of planetary
orbits :-)

And God posted an angel with a flaming sword at | Sincerely, M. Randall Holmes
the gates of Cantor's paradise, that the       | Boise State U. (disavows all) 
slow-witted and the deliberately obtuse might | holmes at math.idbsu.edu
not glimpse the wonders therein. | http://math.idbsu.edu/~holmes