Alain Colmerauer (1941–2017) was a French computer scientist who created Prolog. His work on logic programming established a fundamental paradigm where programs express logical relationships rather than sequential instructions.
Background
Colmerauer trained in mathematics and became interested in computational linguistics—using computers to process natural language. This interest led him to explore logic as a programming foundation.
Creating Prolog
At the University of Aix-Marseille in 1972, Colmerauer developed Prolog with Philippe Roussel, building on work by Robert Kowalski on logic as computation. The language emerged from efforts to use logic for natural language processing.
Contributions to NLP
Before Prolog, Colmerauer worked on Q-systems, a formalism for transformational grammars. His interest in parsing and language structure influenced Prolog’s design, particularly its pattern matching and unification features.
Impact on AI
Prolog became central to AI research:
- Expert systems encoded knowledge as Prolog rules
- Natural language processing used Prolog’s pattern matching
- Japan’s Fifth Generation Computing project adopted Prolog
- Constraint logic programming extended Prolog’s ideas
Legacy
Though Prolog is less prominent than in its 1980s heyday, logic programming concepts persist in Datalog, answer set programming, and declarative approaches throughout computing. Colmerauer demonstrated that programming could be based on logic rather than imperative steps.