Computer Science for IGCSE & O level - Boolean Logic (Section 8 - No. 45)
How can one obtain a NOT gate using a NAND gate?
Connect both inputs of the NAND gate together.
Connect one input of the NAND gate to VCC.
Connect one input of the NAND gate to GND.
Use two NAND gates in series.
Explication
Connecting both inputs of a NAND gate together effectively inverts the input.