29308261
Epistemic Entrenchment and Arithmetical Hierarchy
Abstract If the underlying theory is sufficiently rich (e.g. like first-order arithmetic), then no epistemic entrenchment preorder of sentences is recursively enumerable. Consequently, the set of all defeasible proofs (determined by such a fixed preorder) is not recursively enumerable and hence, a fortiori, nonrecursive. On the other hand there is a satisfactorily rich epistemic entrenchment preorder
120841015
SYSTEMS OF CONDITIONAL BELIEFS IN DEMPSTER-SHAFER THEORY AND EXPERT SYSTEMS
Various notions of soundness for systems of conditional beliefs are introduced and interrelated (the term “belief” being used in the sense of Dempster-Shafer theory). An application to the analysis of the use of Dempster-Shafer theory in classical (rule-based, MYCIN-like) expert systems is sketched. Some open problems are formulated.
44650386
Fuzzy Logic and Arithmetical Hierarchy, II
A very simple many-valued predicate calculus is presented; a completeness theorem is proved and the arithmetical complexity of some notions concerning provability is determined.
205092353
A simple dynamic logic
Abstract A system of dynamic predicate logic is presented. It allows nonstandard modelling of time, which makes recursive axiomatization possible, and is essentially one-sorted (the same elements code data and time), which makes the system reasonably simple and transparent. The system is subjected to usual mathematical considerations; in particular, it is shown to be equivalent to the three-sorted system due to Andreka, Nemeti and Sain (1982). A conservation result for the latter system is obtained as a by-product.
122713833
GETTING BELIEF FUNCTIONS FROM KRIPKE MODELS
61701554
Metamathematics of Fuzzy Logic
Preface. 1. Preliminaries. 2. Many-Valued Propositional Calculi. 3. Lukasiewicz Propositional Logic. 4. Product Logic, Godel Logic. 5. Many-Valued Predicate Logics. 6. Complexity and Undecidability. 7. On Approximate Inference. 8. Generalized Quantifiers and Modalities. 9. Miscellanea. 10. Historical Remarks. References. Index.
15243737
Dual renormings of Banach spaces
We prove that a Banach space admitting an equivalent WUR norm is an Asplund space. Some related dual renormings are also presented.
18639151
Polynomial algebras on classical banach spaces
For the classical Banach spacesX = ℓp,C(K) we identify alln such that every polynomial of degreen + 1 onX is uniformly approximable on the unit ball by elements of the algebra generated by all polynomials of degree up ton onX.