Boolean OR zero

If we have an expression like:

A+0

…then for any value of A, we are ORing it with 0. If we and anythign with 0, then we get that thing back.

We know that, because of the OR truth table:

• 1 OR 0 = 1
• 0 OR 0 = 0, so:
• A OR 0 = A
• (because the first number above is what we end up getting)

In short:

A+0=A

We can use this to simplify boolean algebra!

We can replace anywhere we see A+0 with A