1. This question is about lexing, parsing, and CFGs (= context free grammars).(a) For each of the following statements about ASTs (= abstract syntaxtrees), state whether they are true or false.Correct answers areawarded2marks; wrong answers are penalised by1mark (to a minimumof0marks for this question).Omitted answers do not contributepositively or negatively to your grade.[14 marks]i. The lexer takes as input a list of tokens, representing a program.ii. The lexer produces an AST from the list of tokens.iii. The token list is produced in the semantic analysis stage.iv. The purpose of the lexing phase is to make it easier to adapt acompiler to new machine architectures (such as moving from Intelto ARM processors).v. The purpose of constructing an AST is to represent the structure ofthe computer program, to simplify code generation.vi. The purpose of constructing an AST is to allow the compiler togenerate faster executable machine code.vii. Dynamically typed languages like Python and Javascript dont needto do lexing and parsing.

1. This question is about lexing, parsing, and CFGs (= context free grammars). (a) For each of the following statements about ASTs (= abstract syntax trees), state whether they are true or false. Correct answers are awarded 2 marks; wrong answers are penalised by 1 mark (to a minimum of O marks for this question). Omitted answers do not contribute positively or negatively to your grade. [14 marks] i. The lexer takes as input a list of tokens, representing a program. ii. The lexer produces an AST from the list of tokens. iii. The token list is produced in the semantic analysis stage. iv. The purpose of the lexing phase is to make it easier to adapt a compiler to new machine architectures (such as moving from Intel to ARM processors). v. The purpose of constructing an AST is to represent the structure of the computer program, to simplify code generation. vi. The purpose of constructing an AST is to allow the compiler to generate faster executable machine code. vii. Dynamically typed languages like Python and Javascript don't need to do lexing and parsing