Chomsky's Hierarchy II

The hierarchy is motivated by the required techniques to find derivations for a given string out of terminal symbols and the typical application domain:

Type 0 grammars allow to generate all languages that can be recognized by a Turing machine.

Type 1 grammars (context-sensitive) can be recognized by linear-bounded nondeterministic Turing machines.

Type 2 grammars (context-free) can be recognized by non-deterministic push-down automatons. Most programming languages can be described by such a grammar.

Type 3 grammars (regular) can be recognized by finite state automatons. Usually, the tokens of programming languages (i.e. identifiers, literals, delimiters etc) can be recognized by regular grammars.

	Type 0 grammars allow to generate all languages that can be recognized by a Turing machine.
	Type 1 grammars (context-sensitive) can be recognized by linear-bounded nondeterministic Turing machines.
	Type 2 grammars (context-free) can be recognized by non-deterministic push-down automatons. Most programming languages can be described by such a grammar.
	Type 3 grammars (regular) can be recognized by finite state automatons. Usually, the tokens of programming languages (i.e. identifiers, literals, delimiters etc) can be recognized by regular grammars.