There are two off-by-one bugs at the end of "Boolean Algebra" section:
A great use of the AND operator is to do a modulo of a number to a power of 2. For example, AND with 3 gets you a result between 0 and 2. AND with 7 gets you a result between 0 and 8.
There are two off-by-one bugs at the end of "Boolean Algebra" section: