ABSTRACT
An integer p > 1 is called prime if its only positive integral divisors are 1 and p. Equivalently, p is prime if and only if p|ab implies p|a or p|b. An integer n > 1 is called composite if it is not prime, that is, if n has an integral divisor u with 1 < u < n. The integer 1 is treated as neither prime nor composite.
