Boolean OR one

If we have an expression like:

A+1

…then for any value of A, we are ORing it with 1. If we or anything with 1, then we just get 1 (because at least one is 1, so OR must be true (1)).

We know that, because of the OR truth table:

• 1 OR 1 = 1
• 0 OR 1 = 1, so:
• A OR 1 = 1
• (because A must represent either a 1 or a 0)

In short:

A+1=1

We can use this to simplify boolean algebra!

We can replace anywhere we see A+1 with 1