[cousin_it]

If both 1 * -1 = -1 and -1 * -1 = -1, then -1 / -1 has two solutions.

[throwaway2245]

Sure, but having a unique solution is not a required property of integer division.

Parallel to your statement: If both 1 * 0 = 0 and 2 * 0 = 0, then 0 / 0 has two solutions.