Not AND.
The
Boolean function which is true unless both its arguments
A NAND B = NOT (A AND B) = (NOT A) OR (NOT B)
A | B | A NAND B
--+---+---------
F | F | T
F | T | T
T | F | T
T | T | F
NAND, like
NOR, forms a complete set of
Boolean functions
on its own since it can be used to make NOT, AND, OR and any
other Boolean function:
NOT A = A NAND A
A AND B = NOT (A NAND B)
A OR B = (NOT A) NAND (NOT B)
(1995-01-24)