XNOR

By adding another function bit to bitwise negate A as well, we can include all possible (non-identity) bitwise operations (NOT, AND, OR, NAND, NOR, XOR, XNOR).

Babbage-Boole Digital Arithmetical and Logical Mill: Part 1 « The Half-Baked Maker 2009

Applying a set of rules to the combination of bits at a given pixel (in the case of this Demonstration, XNOR) reveals the message, which might look like this:

Wolfram Blog : 2008 : June 2008

Applying a set of rules to the combination of bits at a given pixel (in the case of this Demonstration, XNOR) reveals the message, which might look like this:

Wolfram Blog : Secret Codes in The Wolfram Demonstrations Project (But No Dinosaurs) 2008

When using NOR, XNOR takes four NORs and XOR takes five.

The Code Project Latest Articles 2009

Here the exclusive nor (XNOR) returns "true" if input a1 and a2 are identical, and returns "false" if they are different.

PLoS ONE Alerts: New Articles 2008

If the grouping of (a1 XNOR a2) returns true, the search can stop.

PLoS ONE Alerts: New Articles Jin Fan et al. 2008

Here the exclusive nor (XNOR) returns "true" if input a1 and a2 are identical, and returns "false" if they are different.

PLoS ONE Alerts: New Articles Jin Fan et al. 2008