problem 10 consider the following grammar for postfix expression postfix -> number postfix2

Consider the following grammar for postfix expressions. (The symbol EMPTY in the grammar means that we produce an empty string) Postfix -> Number Postfix2 Postfix2 - Postfix BinOp Postfix2 l UnOp Postfix2 I EMPTY BinopI Number -> any valid Java double Part (a) Draw the parse tree (not the expression tree) for the expression 4 5 + sqrt 3 Part (b) Explain why the abstract syntax tree for the expression 4 5 + sqrt 3 is the same as it was for the previous problem, even though the grammar has changed Part (c) Explain why you can write a recursive descent parser for this grammar Part (d) Write the Java code for the getpostfix() and getPostfix20 methods that would implement a recognizing parser (assume the usual interface to th Tokenizer) private static void getPostfix(Tokenizer tokens) /getPostfix() private static void getPostfix2(Tokenizer tokens) //getPostfix2)