Decidability and undecidability of extensions of second (first) order theory of (generalized) successor

Autor: Calvin C. Elgot, Michael O. Rabin
Rok vydání: 1966
Předmět:
Zdroj: Journal of Symbolic Logic. 31:169-181
ISSN: 1943-5886
0022-4812
DOI: 10.2307/2269808
Popis: We study certain first and second order theories which are semantically defined as the sets of all sentences true in certain given structures. Let be a structure where A is a non-empty set, λ is an ordinal, and Pα is an n(α)-ary relation or function4 on A. With we associate a language L appropriate for which may be a first or higher order calculus. L has an n(α)-place predicate or function constant P for each α < λ. We shall study three types of languages: (1) first-order calculi with equality; (2) second-order monadic calculi which contain monadic predicate (set) variables ranging over subsets of A; (3) restricted (weak) second-order calculi which contain monadic predicate variables ranging over finite subsets of A.
Databáze: OpenAIRE