bar (n.)

A mode of CLASSIFICATION of syntactic categories in X-BAR SYNTAX. Most commonly, zero-bar categories, also called HEADS, are word-level categories; single-bar and double-bar categories, maximal PROJECTIONS, are PHRASAL; single-bar categories are intermediate projections. SINGLE BARS and DOUBLE BARS are often represented by a bar over a category symbol (e.g.  ). The alternative ways of representing bar(s) include primes (e.g. N′, N″), and numerical symbols (e.g. N¹, N² or N¹ , N² ). Zero-bar categories are sometimes represented as N0 or N⁰ . In GENERALIZED PHRASE-STRUCTURE GRAMMAR, bar is a multivalued category feature which can take 0, 1 or 2 as its value.