| The figure to the right provides a listing
of some of the more important logical identities. To the right
of the identity is listed either the property that is the basis
for the identity (for example, idempotence) or the common name
given to the identity (for example, contrapositive). These identities
are provided mainly for reference. In looking over the identities,
think back to your high school algebra class where you learned
various identities for equations. This is exactly analogous.
Logic is also a kind of algebra.