Chapter 4 Context-Based Grammatical Regulation

Abstract

The generation of languages under various contextual restrictions represents perhaps the most natural and significant way of grammatical regulation. Therefore, this comprehensive over-100-page seven-section chapter gives an extensive and thorough coverage of grammars regulated in this way. First, Sect. 4.1 considers classical grammars, including phrase-structure and context-sensitive grammars, as contextually regulated grammars. It pays a special attention to their normal forms and uniform rewriting; thereby, it actually extends the material covered in Sect.3.3. In a sense, Sects.4.2 through 4.6 deal with a single language-generating regulated model—context-conditional grammars. Indeed, Sect. 4.2 introduces their general version and establishes key results concerning them. Sects. 4.3 through 4.6 discusses their special cases—namely, Sects. 4.3–4.6 cover random context grammars, generalized forbidding grammars, semi-conditional grammars, and simple semi-conditional grammars, respectively. Section 4.7 closes this chapter by discussing yet another type of contextually regulated grammars—scattered context grammars. These grammars regulate their language generation so they simultaneously rewrite several prescribed nonterminals scattered throughout sentential forms during derivation steps.