  We give a proof of the inconsistency of PM arithmetic, classical set theory
and related systems, incidentally exposing an error in Goedel's own proof of
Goedel's Theorems. The inconsistency proof, that formulae of the form R and ~R
occur as theorems in the PM-isomorphic system P, proceeds from a reflexive
substitution instance of the first axiom of the propositional calculus (axiom
II.1 of P). Goedel's formalism is used throughout.
