In coroutining mode, if Number1 or Number2 are free variables, the call to \//3 is delayed until these variables are instantiated.
Success: \/(11, 7, 15). \/(11, -7, Result). (gives Result = -5) Fail: \/(1, 2, 4). Error: \/(A, 2, 6). (Error 4). \/(6, 2.0, 6.0). (Error 5). \/(4 + 2, 2, 6). (Error 24). \/(5, 2, r). (Error 24).