Provides functions for parity checking.
Determining the parity of integers is a difficult task. Howecver, as a service to the reader we provide the following function. The function returnTrueIfOdd returns true if applied to an odd integer. As a supplement, the function returnTrueIfNotOdd returns true if applied to an integer that isn't odd. Also, same functions are provided for checking even numbers - returnTrueIfEven, returnTrueIfNotEven.
The author has formally verified that these functions satisfy their specifications.