X-Bar theory represented by X-Bar Schema does exactly that. It allows formulation of several levels of complex relationships between any category and the lexical item contained in it by avoiding redundancy, improving representational adequacy for all constituents and allowing for the appropriate accommodation of all kinds of complex relationships between catch constituent of a phrase, clause or a sentence. In addition, the implementation of X-Bar theory also allows proper solutions for a lot of computational needs that demands the representation of the structural complexity of human language for the purpose of dealing with Natural Language Processing and automation of sentence generation, parsing and several significant breakthroughs.
INTRODUCTION TO LINGUISTICS & PHONETICS - X-BAR THEORY