Formal Languages Questions
The main difference between a non-deterministic finite automaton (NFA) and a context-sensitive grammar is the level of expressive power and the type of language they can represent.
An NFA is a computational model that consists of a finite set of states, an input alphabet, a transition function, a start state, and a set of accepting states. It can be in multiple states at the same time and can have multiple possible transitions for a given input symbol. NFAs are capable of recognizing regular languages, which are a subset of the languages that can be described by context-sensitive grammars.
On the other hand, a context-sensitive grammar is a formal grammar that generates languages that are more powerful than regular languages. It consists of a set of production rules, a start symbol, and a set of non-terminal symbols. The production rules define how the non-terminal symbols can be rewritten into strings of terminal and non-terminal symbols. Context-sensitive grammars can generate languages that have more complex structures and dependencies, allowing them to describe more sophisticated patterns and languages.
In summary, the main difference is that NFAs are limited to recognizing regular languages, while context-sensitive grammars can generate languages that are more powerful and have more complex structures.