The Decidability of the
Class and the Axiom of Foundation
Abstract
We show that the Axiom of Foundation, as well as the Antifoundation Axiom
AFA, plays a crucial role in determining the decidability of the following problem. Given a first-order theory T over the language , and a sentence
F of the form
with
quantifier-free in the
same language, are there models of T in which F is true?
Furthermore we show that the Extensionality Axiom is quite irrelevant in
that respect.
Permanent link to this document: http://projecteuclid.org/euclid.ndjfl/1054301354
Digital Object Identifier: doi:10.1305/ndjfl/1054301354
Mathematical Reviews number (MathSciNet): MR1993389
Zentralblatt MATH identifier: 1023.03007
References
Notre Dame Journal of Formal Logic