Checking divisibility in Developer Help
#define DIVISIBLE(a,b) (!(a%b))
> #define DIVISIBLE(a,b) (!(a%b))>
#define DIVISABLE(a,b) !((a)%(b))proc/divisable(a, b) return !(a % b)
#define DIVISIBLE(a,b) (!(a%b))% is the modulus operator. a%b returns the remainder of a/b, so if it's 0, then a is divisible by b. If it is non-zero, then a is NOT divisible by b.