2. Write the BNF grammar rules for the language whose sentences have the following structure

(b [c] d)+x

This is expressed in EBNF notation, where the + superscript indicates one or more occurrences, and the superscript indicates zero or more occurrences. Alternation is expressed by the (...|...) construct. An optional symbols are enclosed in square brackets: [...].

3. Consider the following grammar

assign id := expr

id A | B | C

expr expr + term | term

term term * factor | factor

factor id | id [ expr ]

Produce a rightmost derivation of this sentence:

A := A * B[C+D]