Language

In the formal study of logic, language, and computation a language is the set of expressions – sentences, strings of symbols – that can be produced from a particular grammar (Chomsky, 1965; Parkes, 2002).  While, by definition, the grammar will be finite – consisting of a finite alphabet of symbols, and a finite set of rules for manipulating these symbols – the language produced by the grammar can be infinite.  That is, the set of expressions generated by a grammar can be an infinite set.  This definition of language is very abstract and computational, and is not concerned with the many performance-related issues that would be of concern to a psycholinguist.

References:

1. Chomsky, N. (1965). Aspects Of The Theory Of Syntax. Cambridge, MA: MIT Press.
2. Parkes, A. (2002). Introduction to Languages, Machines and Logic: Computable Languages, Abstract Machines and Formal Logic. London ; New York: Springer.

(Added September 2010)