In coroutining mode, if Number1 or Number2 are free variables, the call to >>/3 is delayed until these variables are instantiated.
Success: >>(8, 3, 1). >>(17, 3, X). (gives X = 2) Fail: >>(1, 2, 3). Error: >>(A, 2, 6). (Error 4). >>(16, 2.0, 4.0). (Error 5). >>(4 + 12, 2, 4). (Error 24). >>(5, 2, r). (Error 24).