Context Free Grammar Problems

1) What language does the grammar defined by the following rules generate?

dd

dd

c

c

2) Formally define the context free grammar for the set of all rational numbers (all numbers that can be expressed as n/m, both positive and negative).

3) Expand the rules of the language of balanced parenthesis to include coverage for balanced square brackets and balanced curly brackets as well.

4) Create the rules of a C.F.G. which generates the language of legal definitions for primitive variable types in C++ (You will likely want multiple grammar variables).