There usually follows a demonstration of simple AND, OR, and XOR gates made from NAND gates, and maybe a flip-flop or two.

The Dr. has since built AND, NAND, OR, NOR, XOR and XNOR gates, as well as a buffer, incorporating light into every logic gate.

'Nand Game' review to assemble a circuit from scratch using a NAND gate This article, originally posted in Japanese on 21:00 Dec 04, 2020, may contains some machine-translated parts.