------------------------------
|  x  |  y  | x&y | x|y | x^y |
------------------------------
|  0  |  0  |  0  |  0  |  1  |
------------------------------
|  1  |  0  |  0  |  1  |  1  |
------------------------------
|  0  |  1  |  0  |  1  |  1  |
------------------------------
|  1  |  1  |  1  |  1  |  0  |
------------------------------

any pair other above operations can be used to
perform an arbitrary binary arithmetic operation