This is an exposition of Lambek’s strengthening and generalization of the deduction theorem in categories related to intuitionistic propositional logic. Essential notions of category theory are introduced so as to yield a simple reformulation of Lambek’s Functional Completeness Theorem, from which its main consequences can be readily drawn. The connections of the theoremwith combinatory logic, ...

There are many ways in which the query answering process for deductive databases may be optimised. At the heart of many of these methods is some form of constraint on the variables of the query, so that facts which are not relevant to the query are not computed. In this paper we show how fold/unfold transformations may be used to propagate some forms of constraint which are not captured by tech...

In this paper, we will report on the experience of building a successful industrial application using the LDL++ deductive database as part of the technology transfer process to our sponsor company, Eastman Chemical Company. We will describe the nature of the problems faced by Eastman Chemical Company and show how the LDL++ deductive database technology helps to build an Intelligent Information ...

In a nested relational or complex object database, nested tuples and sets are used to represent real world objects. For various reasons, such tuples and sets can be partial or complete. In this paper, we discuss how to support them in deductive databases. In particular, we present a deductive database language RLOG II that supports partial and complete tuples and sets based on Relationlog. This...