Making prolog more expressive

Toward More Expressive Contracts

The principles of Design by Contract form the basis of the Eiffel approach and account for a good deal of its appeal. Eiffel's contracts are the result of a design trade-offbetween the full extent of formal specifications and what is acceptable to practicing software developers. The latter criterion has been critical: The ideas had to be practical; any competent programmer can immediately see t...

Towards More Expressive Cake Cutting

Cake cutting is a playful name for the problem of fairly dividing a heterogeneous divisible good among a set of agents. The agent valuations for different pieces of cake are typically assumed to be additive. However, in certain practical settings this assumption is invalid because agents may not have positive value for arbitrarily small “crumbs” of cake. In this paper, we propose a new, more ex...

The Expressive Power of Side Effects in Prolog

The Making of the Aquarius Prolog System

As part of the Aquarius project at Berkeley we have developed a high performance Prolog system. The performance of the system has reached a milestone: it can run some programs more efficiently than the MIPS C compiler doing its best optimization. In this paper we present performance results and we discuss informally some practical aspects of the implementation techniques that achieved these res...

Native Cardinality Constraints: More Expressive, More Efficient Constraints

Boolean cardinality constraints are commonly translated (encoded) into Boolean CNF, a standard form for Boolean satisfiability problems, which can be solved using a standard SAT solving program. However, cardinality constraints are a simple generalization of clauses, and the complexity entailed by encoding them into CNF can be avoided by reasoning about cardinality constraints natively within a...