ons will be out of phase; the number
      of prey will rise, then after a delay, the predators will rise as the prey
      begins to fall, causing the predator population to crash again.
    </p>

    <p>
      In this program, the pair of ODE's is solved with a simple finite difference
      approximation using a fixed step size.  In general, this is NOT an efficient
      or reliable way of solving differential equations.  However, this program is
      intended to illustrate the ideas of finite differen