Journal of the ACM

We introduce a general framework for constraint satisfaction and optimization where classical CSPs, fuzzy CSPs, weighted CSPs, partial constraint satisfaction, and others can be easily cast. The framework is based on a semiring structure, where the set ...

We show that a Turing machine with two single-head one-dimensional tapes cannot recognize the set.

Object-oriented applications of database systems require database transformations involoving nonstandard functionalities such as set manipulation and object creation, that is, the introduction of new domain elements. To deal with thse functionalities, ...

This paper addresses and answers a fundamental question about resolution. Informally, what is gained with respect to the search for a proof by performing a single resolution step? It is first shown that any unsatisfiable formula may be decomposed into ...

Consider an array of Processing Elements [PEs], connected by a 2-dimensional grid network, and holding at most one operand of an expression in each PE. Suppose that each PE is allowed, in any one parallel step, to receive one item of data from any of ...