The CIAO Multi-Dialect Compiler and System: An Experimentation Workbench for Future (C)LP Systems

CIAO is an advanced programming environment supporting Logic and Constraint programming. It offers a simple concurrent kernel on top of which declarative and non-declarative extensions are added via librarles. Librarles are available for supporting the ISOProlog standard, several constraint domains, functional and higher order programming, concurrent and distributed programming, internet programming, and others. The source language allows declaring properties of predicates via assertions, including types and modes. Such properties are checked at compile-time or at run-time. The compiler and system architecture are designed to natively support modular global analysis, with the two objectives of proving properties in assertions and performing program optimizations, including transparently exploiting parallelism in programs. The purpose of this paper is to report on recent progress made in the context of the CIAO system, with special emphasis on the capabilities of the compiler, the techniques used for supporting such capabilities, and the results in the áreas of program analysis and transformation already obtained with the system

Verifying termination and error-freedom of logic programs with block declarations

We present verification methods for logic programs with delay declarations. The verified properties are termination and freedom from errors related to built-ins. Concerning termination, we present two approaches. The first approach tries to eliminate the well-known problem of speculative output bindings. The second approach is based on identifying the predicates for which the textual position of an atom using this predicate is irrelevant with respect to termination. Three features are distinctive of this work: it allows for predicates to be used in several modes; it shows that block declarations, which are a very simple delay construct, are sufficient to ensure the desired properties; it takes the selection rule into account, assuming it to be as in most Prolog implementations. The methods can be used to verify existing programs and assist in writing new programs

An Overview of F-OML: An F-Logic Based Object Modeling Language

F-OML is an F-Logic based Object Modeling Language. It can be used for extending UML diagrams, reasoning about them, testing UML models, and defining their syntax (meta-modeling) and semantics. This wide range of applications of F-OML stems from several language features, including polymorphism, multi-level object modeling, and model instantiation. F-OML supports modeling of classes and properties. F-OML is layered on top of an elegant formal language of guarded path expressions, called PathLP, which is used to define objects and their types. PathLP is a logic programming language, inspired by F-logic. It supports path expressions, rules, constraints, and queries, and it is easy to implement by translation into a tabling Prolog engine, such as XSB. In this short overview we informally describe the main constructs of PathLP and F-OML, and provide examples that demonstrate the four modes of F-OML usage. Formal definitions and additional details are found in the full paper. Finally, we analyze how language features contribute to its expressiveness, and provide a brief comparison with OCL