NAND Gates in 3D
“You can use 10 NAND gates to simulate a wire crossing, which means that any logic circuit in 3D space can also be implemented in just 2 dimensions.” https://x.com/IsaacKing314/status/1902191519559512204
Logic circuits in the plane: minimal crossovers https://dblp.org/rec/journals/sigact/Dewdney79.html PDF