Context‐free parallel grammars and their applications to generating context‐sensitive languages

Describes intuitively the fact that four types of formal languages can be generated by four types of grammars or can be recognized by four types of automata. Gives the relationships between context‐sensitive languages and computer programming languages. Defines and investigates parallel productions, parallel grammars, and context‐free parallel grammars. Shows that context‐sensitive languages exist which can be generated by context‐free parallel grammars. In addition, states the advantages of context‐free parallel grammars. Also shows that context‐free languages (CFL) are a proper subset of context‐free parallel languages (CFPL). Furthermore, CFPL is a more effective tool for modelling computer programming languages than CFL, especially for parallel computer programming languages, for example, the ADA programming language. Also illustrates context‐sensitive property of recognizing hand‐written characters. The results may have useful applications in artificial intelligence, model parallel computer programming languages, software engineering, expert systems and robotics.