The Complexity of Provable Properties of First Order Theories,
Abstract
This paper considers first order quantified and modal theories with the interpretation of function and predicate symbols restricted to fixed r.e. sets of functions F and predicates R. We characterize functions with certain properties (such as totality, monotonicity, unboundedness) provable in these theories. In the case F and R are restricted to a complexity class (such as polynomial time), our results give a characterization of complexity hierarchies (such as the polynomial time hierarchy of Stockmeyer in terms of strength of theories whose axioms have restricted quantification. In addition we construct formulas for which probability in these theories implies the collapse of the corresponding complexity hierarchy. We consider modal theories as well as purely quantified theories. Because modal formulas can encode arbitrary alternations of quantifiers, probability of certain formulas in these modal theories implies the collapse of complexity hierarchies with unbounded alternation. This is applied to the P = (questionably) PSPACE problem. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1980
- Accession Number
- ADA095656
Entities
People
- John Reif
- Steve Homer
Organizations
- Harvard University