discret math

(2) Here is a context-free grammar that can be used to generate algebraic expressions via the arithmetic operators (addition, subtraction, multiplication, and division), in the variables p, q, and r. The letter E stands for expression:

Rule 1: E —› p

Rule 2: E —› q

Rule 3: E —› r

Rule 4: E —› E + E

Rule 5: E —› E – E

Rule 6: E —› E X E

Rule 7: E —› E/E

Rule 8: E —›(E)

(i). Use the above grammar to derive the string given by the mathematical expression E =  (p + q) X p – r X p/(q + q)

(ii). Provide a parse tree for this derivation.