NOR gate logic, like NAND and NOT/AND/OR gate logic, are functionally-complete.
Combinational logic examples:
- NOT gate -> N-input (N >= 1) NOR with all inputs tied together to the input
- N-input OR gate -> N-input NOR gate with a NOT gate at the output
- N-input AND gate -> N-input NOR gate with a NOT gate in front of each input
- Bonus - sequential logic: S-R latch -> 2x 2-input NOR gates with one each of their inputs tied to the other gate's output