1. What is the value of the following Impcore expression? (if (> 3 5) 17 99) 2. Which of the following best describes the syntactic structure of Impcore? (a) An expression can contain a definition (b) A definition can contain an expression (c) Both of the above (d) None of the above 3. Does this Impcore test pass? Please answer "yes" or "no." (check-expect (+ 1 2 3) 6) Assuming `x` is bound to a global variable, does this Impcore test pass? Again, please answer "yes" or "no." (check-expect (set x 1) 1) Next read Section 1.2, which starts on page 16, about abstract syntax. 4. After reading about abstract syntax, look at this picture of an abstract-syntax tree for a "calculator expression": ![Picture of an abstract-syntax tree](ast.jpg)  Answer these questions: (a) What concrete syntax could you write in C for this expression? (b) What concrete syntax could you write in Impcore for this expression?