Divisibility testing

We can test whether one number evenly divides another using the divides operator. In particular, a divides b is true if there exists an integer k such that b == k*a. For example:

Disco> 3 divides 6
T
Disco> 6 divides 3
F
Disco> 3 divides (-6)
T
Disco> 5 divides 5
T
Disco> 4 divides 6
F
Disco> 0 divides 10
F
Disco> 10 divides 0
T
Disco> 0 divides 0
T
Disco> 1/2 divides 3/2
T