# Racket Assignment

## Overview

The Goldbach conjecture states that every even number greater than two is the sum of two prime numbers. For example:

6 = 3 + 3
12 = 5 + 7
38 = 7 + 31
10000 = 59 + 9941


The conjecture has never been proven, but has shown been shown to hold for every even number greater than two up to at least 4 quintillion.

You will write a program that reads in a number from the user, verifies that it is even and greater than 2, and prints out two prime numbers that sum to the value the user entered.

Example run:

Enter an even value: 91
That number is not even.
Enter an even value: 0
That number is not greater than two.
Enter an even value: 90
The two primes that add to 90 are 7 and 83.


Your program should continue asking for a value until it is given an even number greater than 2.

Using packages from the Racket "Planet" repository is not acceptable.

## Tips

• Start by writing a function that tests whether a number is prime.
• Then write a function that uses this (and filter) to create a list of prime numbers from 2 to the value they entered.
• Once you have a list of primes, recurse over it testing each number.
• There may be multiple pairs of primes that add to the value, any is acceptable.
• Other functions that may come in handy:
• modulo
• member
• even?
• first
• rest

## Submitting

Submit your code by emailing the Racket file to ifinlay@umw.edu.