Note. The results of the entire homework should be kept in one Lisp file named hw2.el to be uploaded to Canvas.

Write a Lisp program and do the following:

• Declare 3 variables, one of which should contain a description.
• Assign numerical values to the three variables.
• Show an example (as many expressions as you want) of using the following mathematical functions, involving the variables you declared: expt, random, abs, cos, truncate.
• Invoke the help on one of the functions listed above and copy it into the program, then comment it out.
  Hint: when editing a file with the extension .el, a menu called Emacs-Lisp should appear in Emacs. You can select the entire region you want to comment out and then use a command in this menu to comment it out.
• Turn the interactive mode on and evaluate your expressions to make sure they are correct.

Implement the following functions in the same file, complete with short descriptions. Do not use loops for these functions (meaning, use recursion when needed), nor built-in functions that can solve the problem directly.

• A function with a single parameter called prod-list that returns the product of the elements of a list. We can assume that the argument is a list containing only numbers. If the list is empty, the function should return 0.
  Hint: use recursion combined with the functions car and cdr.
• A function called is-in-list that takes two parameters, the first being a list and the second a value, and returns true (t) if the value is in the list and false (nil) if not. Use the function equal to test for equality of two values.
• A function called median taking 3 arguments and computing the median of them. For example, if the arguments are 5, 2 and 4, the median is 4. This function should not be recursive. Note that some of the arguments can be equal to each other: the median of 7, 3, and 7 is 7.

Evaluate all of these functions and show a few examples of testing them and comment out the results. Add a comment at the top with your name and homework number.