Automorphisms of Recursively Saturated Models of Arithmetic

  title={Automorphisms of Recursively Saturated Models of Arithmetic},
  author={Richard Kaye and Roman Kossak and Henryk Kotlarski},
  journal={Ann. Pure Appl. Logic},
Kaye, R., R. Kossak and H. Kotlarski, Automorphisms of recursively saturated models of arithmetic, Annals of Pure and Applied Logic 55 (1991) 67-99. We give an examination of the automorphism group Aut(M) of a countable recursively saturated model M of PA. The main result is a characterisation of strong elementary initial segments of M as the initial segments consisting of fixed points of automorphisms of M. As a corollary we prove that, for any consistent completion T of PA, there are… CONTINUE READING