Date: Mar 15, 2013 4:21 AM
Author: Graham Cooper
Subject: Re: Number of variables needed to axiomatize first order predicate calculus?

On Mar 13, 5:56 pm, George Greene <> wrote:
> On Mar 9, 7:20 am, Rupert <> wrote:

> > I can't see how an axiomatisation of first-order predicate calculus
> >  using a finite number of individual variables would ever do justice
> >  to all of the first-order predicate calculus.
> >  There's no finite upper bound on the number of individual variables that can occur in a formula.

> That's not really a reasonable objection.
> There is no finite upper bound on the number of propositional letters
> that can occur in a proposition EITHER,
> yet they handled it.  Obviously you would handle THAT in basically the
> same way, with a class of variables
> ranging over all formulas.

Use words, not letters!