Write a CFG to generate identifiers (IDs) in Java Programming Language.

a. An ID in Java is a string of characters consisting of letters (upper-case or lower- case), digits, underscores _, or dollar sign $, and it cannot start with a digit.

2. For the identifier $$_12u$P , use your grammar created in problem 1 to :

a. give a derivation

b. draw the tree for the derivation for the identifier