Question

question about the definition of greatest common divisor?

Answer 1

If a and b are integers, not both zero, then an integer d is called the greatest common divisor of a and b if
i) d > 0
ii) d is a common divisor of a and b; and
iii) each integer m that is a divisor of a and b is also a divisor of d.

explain the (iii) third condition