7 and 8

0 ayles 0 0 7.Give cont ext-free grammars generating the following languages. a) The set of strings over the alphabet = (a, b) with twice as many a's as b's. b) The complement of the language (a b In20). 8.Using the following context-free grammar F -+ (E) I a Give parse trees and leftmost derivations for the following strings. 1. a 2. a (ata) 3. atata