Al says he can prove that all sheep in a flock are the same color:

Base case: One sheep. It is clearly the same color as itself.
Induction step: A flock of n sheep. Take a sheep, a, out. The remaining n−1 are all the same color by induction. Now put sheep a back in and take out a different sheep, b. By induction, the n−1 sheep (now with a) are all the same color. Therefore, all the sheep in the flock are the same color. What is wrong with Al’s “justification”?