Q-systems
From Wikipedia, the free encyclopedia
The Q-Systems are a method of directed graph transformations according to given grammar rules, developed at the Université de Montréal by Alain Colmerauer in the late 1960's for use in natural language processing. The Université de Montréal's machine translation system, TAUM-73, used the Q-Systems as its language formalism.
Each Q-System consists of a set of rewriting rules, which apply to the sentence, which is represented by a directed acyclic graph, using one-way unification. The output of the analysis is again a directed graph (usually containing only one edge); this allows several Q-Systems to be chained, each of them performing a specialized task, together forming a complex system. For example, TAUM 73 consisted of fifteen chained Q-Systems.
Further refinement of the ideas in Q-Systems led to Prolog, designed by Colmerauer along with Robert Kowalski in the 1970's.
[edit] References
- Colmerauer, A: Les systèmes Q ou un formalisme pour analyser et synthétiser des phrases sur ordinateur. Mimeo, Montréal, 1969.
[edit] External links
- The birth of Prolog (PDF) — describes the Q-systems in Part II