Merge (usually capitalized) is one of the basic operations in the
Minimalist Program, a leading approach to
generative syntax, when two syntactic objects are combined to form a new syntactic unit (a
set). Merge also has the property of
recursion in that it may apply to its own output: the objects combined by Merge are either
lexical items or sets that were themselves formed by Merge. This recursive property of Merge has been claimed to be a fundamental characteristic that distinguishes language from other cognitive faculties. As
Noam Chomsky (1999) puts it, Merge is "an indispensable operation of a recursive system ... which takes two syntactic objects A and B and forms the new object G={A,B}" (p. 2).