---
|     0 | 0 0
|     1 | 0 1

JA:  Since binary operations are ternary relations,
     these can also be written as relational tables:

o-----o-----o---------o
|  x  |  y  | z = x+y |
o-----o-----o---------o
|  0  |  0  |    0    |
|  0  |  1  |    1    |
|  1  |  0  |    1    |
|  1  |  1  |    0    |
o-----o-----o---------o

o-----o-----o---------o
|  x  |  y  | z = x.y |
o-----o-----o---------o
|  0  |  0  |    0    |
|  0  |  1  |    0    |
|  1  |  0  |    0    |
|  1  |  1  |    1    |
o-----o-----