Changes

This principle can be useful to prove apparently difficult problems.  For example, this principle can easily prove that at least two people in New Jersey must have precisely the same number of hairs on their head.  This is because there are more people living in New Jersey than possible numbers of hairs on one's head.

This principle can be useful to prove apparently difficult problems.  For example, this principle can easily prove that at least two people in New Jersey must have precisely the same number of hairs on their head.  This is because there are more people living in New Jersey than possible numbers of hairs on one's head.