Logic programming synthesis and transformation are methods are deriving logic programs from their specifications and, where necessary, producing alternative but equivalent forms of a given program. The techniques involved in synthesis and transformation are extremely important as they allow the systematic construction of correct and efficient programs and have the potential to enhance current methods of software production. Transformation strategies are also being widely used in the field of logic program development. LOPSTR 91 was the first workshop to deal exclusively with both logic program synthesis and transformation and, as such, filled an obvious gap in the existing range of logic programming workshops. In attempting to cover the subject as comprehensively as possible, the workshop brought together researchers with an interest in all aspects of logic (including Horn Clause and first order logic) and all approaches to program synthesis and transformation. Logic Program Synthesis and Transformation provides a complete record of the workshop, with all the papers re-produced either in full or as extended abstracts. They cover a wide range of aspects, both practical and theoretical, including the use of mode input-output in program transformation, program specification and synthesis in constructive formal systems and a case study in formal program development in modular Prolog. This volume provides a comprehensive overview of current research and will be invaluable to researchers and postgraduate students who wish to enhance their understanding of logic programming techniques.