The Figure L4-1 shows the NOR gate symbols together with its truth table.
NAND gate can convert to all simple logic gates similar NOR gates as follows :
NOT gate conversion with connect both inputs together followign the Figure
L4-2
AND gate conversion connect 2 NAND gates. One acts simple NAND gate,
another acts NOT gate following the Figure L4-3. The Boolean expression for this conversion
will be: