<LI>Define an `xor` operator. If you haven't seen this term before, here's a truth table:
- true xor true = false
- true xor false = true
- false xor true = true
- false xor false = false
+ true xor true == false
+ true xor false == true
+ false xor true == true
+ false xor false == false
<LI>Inspired by our definition of boolean values, propose a data structure