What is the logical operator NOR?

Question

Does not exist:

! (a or b)
! a or! b
! (a and b)

something else?

Answer 1

! (a or b)

see http://en.wikipedia.org/wiki/Logical_NOR for more:

, , , . (p NOR q) , p, q - .. p q . grammar, ...

Answer 2

! (a b)

Answer 3

NOR(a, b) NOT(OR(a, b)), !(a or b) . De Morgan Laws, (!a) and (!b).

Answer 4

: ! (a b)

! a ! b

Answer 5

((a NAND a) NAND (b NAND b)) NAND ((a NAND a) NAND (b NAND b)), , .:)