Automorphisms Moving all Non-Algebraic Points and an Application to NF
Korner, Friederike
J. Symbolic Logic, Tome 63 (1998) no. 1, p. 815-830 / Harvested from Project Euclid
Section 1 is devoted to the study of countable recursively saturated models with an automorphism moving every non-algebraic point. We show that every countable theory has such a model and exhibit necessary and sufficient conditions for the existence of automorphisms moving all non-algebraic points. Furthermore we show that there are many complete theories with the property that every countable recursively saturated model has such an automorphism. In Section 2 we apply our main theorem from Section 1 to models of Quine's set theory New Foundations (NF) to answer an old consistency question. If NF is consistent, then it has a model in which the standard natural numbers are a definable subclass $\mathbb{N}$ of the model's set of internal natural numbers Nn. In addition, in this model the class of wellfounded sets is exactly $\bigcup_{n\in \mathbb{N}}\mathscr{P}^n(\varnothing)$.
Publié le : 1998-09-14
Classification: 
@article{1183745568,
     author = {Korner, Friederike},
     title = {Automorphisms Moving all Non-Algebraic Points and an Application to NF},
     journal = {J. Symbolic Logic},
     volume = {63},
     number = {1},
     year = {1998},
     pages = { 815-830},
     language = {en},
     url = {http://dml.mathdoc.fr/item/1183745568}
}
Korner, Friederike. Automorphisms Moving all Non-Algebraic Points and an Application to NF. J. Symbolic Logic, Tome 63 (1998) no. 1, pp.  815-830. http://gdmltest.u-ga.fr/item/1183745568/