[FOM] Mendelson's missing appendix on the consistency of PA
ps218 at cam.ac.uk
Tue Feb 12 15:14:14 EST 2013
In the first edition of Elliott Mendelson's classic *Introduction to
Mathematical Logic* (1964) there is an appendix, giving a version of
Schütte's (1951) variation on Gentzen's proof of the consistency of PA.
This is intriguing stuff, crisply and quite accessibly presented. The
appendix is, however, suppressed in later editions (in fact, from the
second onwards), even though there is plenty of room given to other
materials and a new appendix
Now, a number of people have said that the appendix is one of the most
interesting things about the book. I agree. I too remember being quite
excited by it when I first came across it a long time ago!
So: has anyone heard a folkloric story about why Mendelson suppressed the
appendix? I've never heard it suggested that there is a problem with the
consistency proof as given.
Context, if you are interested: I asked this a couple of weeks ago on
math.SE (without getting an answer) when starting to write up a survey of
some of the Big Books on Mathematical Logic that will become part of my
Teach-Yourself-Logic Guide (mostly for philosophers, though others might be
interested), and I'd got to Mendelson. You can get the current version of
the Guide by going to http://www.logicmatters.net/students/tyl/
Dr Peter Smith: Faculty of Philosophy, University of Cambridge
More information about the FOM