  This is a tutorial for the many-worlds theory by Everett, which includes some
of my personal views. It has two main parts.The first main part shows the
emergence of many worlds in a universe consisting of only a Mach-Zehnder
interferometer. The second main part is an abridgment of Everett's long thesis,
where his theory was originally elaborated in detail with clarity and rigor.
Some minor comments are added in the abridgment in light of recent
developments. Even if you do not agree to Everett's view, you will still learn
a great deal from his generalization of the uncertainty relation, his unique
way of defining entanglement (or canonical correlation), his formulation of
quantum measurement using Hamiltonian, and his relative state.
