Questions for GEB Unit XIV

Mårten Stenius URL: http://www.nada.kth.se/~d90-mst/courses/geb/q14.html

Page and figure references are from the English Penguin Books edition, unless otherwise noted.

Dialogue XIV: Air on G's String

What about:
"IS NOT A SENTENCE FRAGMENT" IS NOT A SENTENCE FRAGMENT.
(p. 435 and 437)

Chapter XIV: On Formally Undecidable Propositions of TNT and Related Systems

At the lower half of p. 449, Hofstadter says: "...since the rules of the Propositional Calculus ensure that all well-formed formulas of the form <Pv~P> are theorems." I always (intuitively?) thought that P needed to be a theorem, too - not just well-formed...? I'm confused.