Alain Colmerauer is known as a pioneer of Artificial Intelligence and the author of the famous programming language Prolog. He was a mathematician and a computer scientist, a tireless and visionary researcher, who very quickly identified the need to move away from the traditional programming system and towards a logical approach.

In 1969 at Montreal University he developed “Q systems”, a formalism suited for processing natural languages, which was the predecessor of Prolog. The first Prolog interpreter was written in 1971 at Marseille University.

This first academic success brought Prolog and its creator to the attention of many universities and research centers, and the language was spread all over the world. Prolog II introduced constraint logic programming, while Prolog III and Prolog IV apply the solving technique of constraints resolution and intervals propagation to discrete and continuous domains. This last development, partly unfinished, was the last one of the long line of his Prologs and of his life.

Prolog development and applications illustrate perfectly the kind of scientist he was: always concerned with theory as well as practical implementations.

Three years after his death, this tribute will recall his important scientific contribution and will showcase the links between his work and the research still going on today. In a context that has become particularly active due to the recent development of numerical techniques in AI, we will have an update of the symbolic approaches that have historically founded AI research at Marseille. We expect this day to be an opportunity for evoking last research developments in the field.