In addition to the logical operations defined here – computer scientists have defined two other operations (which are merely abstractions of operations defined in my previous article) since they are used so often. They are NAND and NOR, symbolically ↑ (|) and ↓ (⊥). I say they are abstractions because they are simply the negation of AND and OR operations
NAND
| A |
B |
A AND B |
NOT (A AND B) |
A NAND B |
| 1 |
1 |
1 |
0 |
0 |
| 1 |
0 |
0 |
1 |
1 |
| 0 |
1 |
0 |
1 |
1 |
| 0 |
0 |
0 |
1 |
1 |
NOR
| A |
B |
A OR B |
NOT (A OR B) |
A NOR B |
| 1 |
1 |
1 |
0 |
0 |
| 1 |
0 |
1 |
0 |
0 |
| 0 |
1 |
1 |
0 |
0 |
| 0 |
0 |
0 |
1 |
1 |
logic nand nor