 Moreover, as "a" and "b" are both odd, "c" is even, the process can be continued with the pair ("a", "b") replaced by the smaller numbers ("c"/2, "b") without changing the gcd.Each of the above steps reduces at least one of "a" and "b" while leaving them non-negative and so can only be repeated a finite number of times.Thus eventually the process results in "a" = "b", the stopping case.