1. Abramson, H., Unification-Based Conditional Binding Constructs, Proceedings of the First International Logic Programming Conference, Marseille, France, September, 1982.
2. Ahmad, S., Logic Program Control in Logic, Technical Report, Department of Computer Science, Imperial College, London, 1982.
3. Aida, H., Tanaka, H. and Moto-Oka, T., A Prolog Extension for Handling Negative Knowledge, New Generation Computing 1,(1983), Springer Verlag.
4. Aiello, L., Evaluating Functions Designed in First Order Logic, Workshop on Logic Programming, Debrecen, Hungary, July 1980.
5. Aiello, L., Attardi, G. and Primi, G., Towards a More Declarative Programming Style, in Formal Description of Programming Concepts, J. Neuhold, (ed.), North-Holland, New-York, 1978.