2. a) Discuss the impact of left recursion of a grammar during top-down parsing. b) Let you have assigned a task to develop a lexical error recovery module for a compiler. Analyze and discuss the possibility to develop such a module which can recover the lexical errors effectively. c) Write a Lex program which can count and display different types of tokens from an input. Types of tokens are vowels, consonants, digits, white spaces, special symbols (#, !, { }, ;) and unknown. Unknown is a type of alphabet not falls in known token types. Sequence of consecutive white spaces will be treated as a single white space. The Lex program should skip newlines from the input.