conception of sentence logic, the binary division of the clause into subject and predicate was not possible. It therefore opened the door to the dependency relation (although the dependency relation had also existed in a less obvious form in traditional grammars long before Frege). The dependency relation was first acknowledged concretely and developed as the basis for a comprehensive theory of syntax and grammar by Lucien Tesnière in his posthumously published work Éléments de syntaxe structurale (Elements of Structural Syntax). The dependency relation is a one-to-one correspondence: for every element (word or morph) in a sentence, there is just one node in the syntactic structure. The distinction is thus a graph-theoretical distinction. The dependency relation restricts the number of nodes in the syntactic structure of a sentence to the exact number of syntactic units (usually words) that that sentence contains. Thus the two word sentence Luke laughed implies just two syntactic nodes, one for Luke and one for laughed. Some prominent dependency grammars are listed here: Functional generative description Lexicase Link grammar Meaning-text theory Operator grammar Recursive categorical syntax, sometimes called algebraic syntax Word grammar Since these grammars are all based on the dependency relation, they are by definition NOT phrase structure grammars. Non-descript grammars Other grammars generally avoid attempts to group syntactic units into clusters in a manner that would allow classification in terms of the constituency vs. dependency distinction. In this respect, the following grammar frameworks do not come down solidly on either side of the dividing line: Cognitive grammar Construction grammar Stochastic grammar See also Catena Notes References Allerton, D. 1979. Essentials of grammatical theory. London: Routledge & Kegan Paul. Borsley, R. 1991. Syntactic theory: A unified approach. London: Edward Arnold. Chomsky, Noam 1957. Syntactic structures. The Hague/Paris: Mouton. Matthews, P. Syntax. 1981. Cambridge, UK: Cambridge University Press, . McCawley, T. 1988. The syntactic phenomena of English, Vol. 1. Chicago: The University of Chicago Press. Mel'cuk, I. 1988. Dependency syntax: Theory and practice. Albany: SUNY Press. Sag, I. and T. Wasow. 1999. Syntactic theory: A formal introduction. Stanford, CA: CSLI Publications. Tesnière, Lucien 1959. Éleménts de syntaxe structurale. Paris: Klincksieck. van Valin, R. 2001. An introduction to syntax. Cambridge, UK: Cambridge University Press. Generative syntax Syntax Noam Chomsky Natural language processing