OR-AND-invert

They can be efficiently implemented in logic families like CMOS and TTL.

OR-AND-invert gates implement the inverted product of sums.

A 2-1-OAI gate realizes the function with the truth table shown below.

A 2-2-OAI gate realizes the function with the truth table shown below.

[1] One possibility of implementing an XOR gate is by using a 2-2-OAI-gate with non-inverted and inverted inputs.

Symbol for an 2-1 OAI-gate. The OR gate has the inputs A and B.
Implementation of a 3-1 OAI-gate in CMOS
Implementation of an XOR gate using a 2-2-OAI gate