Gates library

The Gates library includes a variety of common components, all of which have a single output whose value is dictated entirely by the component's current inputs.

NOT Gate — inverts a signal
Buffer — does nothing, no-op
AND, OR, NAND, NOR, XOR, XNOR Gates — common logic operations
Odd Parity, Even Parity — parity operations
Tri-state Buffer, Tri-state Inverter — gates with three possible outputs
PLA — Programmable Logic Array

Up to Library Reference