Ralph Becket

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There is no standard modelling language for constraint programming (CP) problems. Most solvers have their own modelling language. This makes it difficult for modellers to experiment with different solvers for a problem. In this paper we present MiniZinc, a simple but expressive CP modelling language which is suitable for modelling problems for a range of(More)
The logic programming language Mercury is designed to support programming in the large. Programmer declarations in conjunction with powerful compile-time analysis and optimization allow Mercury programs to be very efficient. The original design of Mercury did not support constraint logic programming (CLP). This paper describes the extensions we added to(More)
MiniZinc arose as a response to the extended discussion at CP2006 of the need for a standard modelling language for CP. This is a challenging problem, and we believe MiniZinc makes a good attempt to handle the most obvious obstacle: there are hundreds of potential global constraints, most handled by few or no systems. A standard input language for solvers(More)
We describe an implemented spoken-language dialogue system for a travel-planning domain, which accesses a commercially available travel-information web-server and supports a exible mixed-initiative dialogue strategy. We argue, based on data from initial Wizard-of-Oz experiments , that mixed-initiative strategies are appropriate for many types of user, but(More)
In this paper we describe how the translation methodology adopted for the Spoken Language Translator (SLT) addresses the characteristics of the speech translation task in a context where it is essential to achieve easy customization to new languages and new domains. We then discuss the issues that arise in any attempt to evaluate a speech translator, and(More)
MiniZinc arose as a response to the extended discussion at CP2006 of the need for a standard modelling language for CP. This is a challenging problem, and we believe MiniZinc makes a good attempt to handle the most obvious obstacle: there are hundreds of potential global constraints, most handled by few or no systems. We have now used MiniZinc for 2 years,(More)
GraphPlan style planning techniques have generated a substantial amount of interest since they were introduced five years ago. GraphPlan alternates between plan graph generation and searching the plan graph. Attention has so far focused almost exclusively on the search aspects of the problem. However, I claim that existing plan graph generation algorithms(More)