We describe a novel logic, called HiLog, and show that it provides a more suitable basis for logic programming than does traditional predicate logic. HiLog has a higher-order syntax and allows arbitrary terms to appear in places where predicates, functions and atomic formulas occur in predicate calculus. But its semantics is first-order and admits a sound and complete proof procedure. Applications of HiLog are discussed, including DCG grammars, higher-order and modular logic programming, and deductive databases.

This paper describes various techniques for enriching unification-based grammatical formalisms with notational devices that are compiled into categories and rules of a standard un'cation grammar. This enables grammarians to avail themselves of apparently richer notations that allow for the succinct and relatively elegant expression of grammatical facts, while still allowing for efficient processing for the analysis or synthesis of sentences using such grammars

Parsing has been a traditional workbench for showing the virtues of declarative programming. Both logic and functional programming claim the ability of writing parsers in a natural and concise way. We address here the task from a functional-logic perspective. By modelling parsers as non-deterministic functions we achieve a very natural manner of building parsers, which combines the nicest properties of the functional and logic approaches. In particular, we are able to easily define within our framework parsers in a style very close to the `monadic parsers' of functional programming, but without any syntactic overhead. In a different direction we show that, if the functional-logic setting permits higher-order patterns while defining functions, parsers can be freely manipulated as data. This allows programming useful metalevel analysis or transformations, like discovering if the grammar corresponding to a given parser is LL(1). Finally, we sketch the potential application to parsing of f...