Such rules have been proved to form a Context-free grammar.

Given a context-free grammar, does it describe a regular language?

Context-free grammars do not take into account any additional information.

At a higher level of complexity are the context-free grammars (type 2).

The parser works on strings from a particular context-free grammar.

Meta-rules are restricted to those defined by a context-free grammar.

In particular, the design rules describing how to combine different kinds of parts form context-free grammars.

It can express the entire range of context-free grammars.

This method will work only when translation from input to output is equivalent to a context-free grammar.

Shm-reduplication has been advanced as an example of a natural language phenomenon that cannot be captured by a context-free grammar.