Logic gates: NAND and NOR

NOR gate

A digital circuit that produces a LOW output when any of its inputs are HIGH

Negative-OR

The operation of a NAND gate when the asserted states of the inputs are LOW

Negative-AND

The operation of a NOR gate when the asserted states of the inputs are LOW

DeMorgan's theorems

Two Boolean theorems that relate to the complementation of products and sums.

NAND gate

a digital circuit that produces a LOW only when all of its inputs are HIGH

A NAND gate

is equivalent to an AND gate followed by an inverter (NOT)

A NOR gate

is equivalent to an OR gate followed by an inverter (NOT)

DeMorgan's first theorem

states that the complement of a product of variables is equal to the sum of the complements of the variables.

DeMorgan's second theorem

states that the complement of a sum of variables is equal to the product of the complements of the variables