Hierarchical Constraint Logic Programming Languages

约束逻辑程序设计（CLP）是一种通用的 扩展逻辑编程语言以包括约束。 然而，CLP语言以及大多数其他基于约束的 语言和系统，只允许程序员指定 必须遵守的约束。 在许多应用中，例如交互式 图形、页面布局和决策支持，需要表达 既有优惠，又有严格的要求。 作者设计了 CLP方案的一个推广，层次约束逻辑 编程（HCLP），它允许程序员表达所需的 和偏好约束，具有任意数量的强度， 偏好 HCLP的开发将在实践方面继续进行， 一个目标是改进语言实例的实现 方案，包括纳入有效的约束求解器， 增加了比较潜在解决方案的新方法。 其效用将是 通过使用交互式图形，以及文档格式， 决策支持和调度，作为测试应用程序。 上 理论方面，计划扩展约束层次结构 形式主义，包括只读变量和偏序 等级制度

Constraint Logic Programming (CLP) is a general scheme for extending logic programming languages to include constraints. However, CLP languages, as well as most other constraint-based languages and systems, only allow the programmer to specify constraints that must hold. In many applications, such as interactive graphics, page layout, and decision support, one needs to express preferences as well as strict requirements. The authors have designed a generalization of the CLP scheme, Hierarchical Constraint Logic Programming (HCLP), which allows a programmer to express both required and preferential constraints, with an arbitrary number of strengths of preference. Development of HCLP will continue on the practical side, a goal is to improve the implementation of an instance of the language scheme, including incorporating efficient constraint solvers and adding new ways of comparing potential solutions. Its utility will be tested by using interactive graphics, as well as document formatting, decision support, and scheduling, as test applications. On the theoretical side, it is planned to extend the constraint hierarchy formalism to include read-only variables and partially ordered hierarchies.