- Spaceballs is a 1987 American space opera parody film co-written, produced and directed by Mel Brooks. It primarily parodies the original Star Wars trilogy, but also of other popular franchises such as Star Trek, Alien, The Wizard of Oz, 2001: A Space Odyssey, Planet of the Apes, and Transformers. The film stars Bill Pullman, John Candy, and Rick Moranis, with the supporting cast including Daphne Zuniga, Dick Van Patten, George Wyner, Lorene Yarnell, and the voice of Joan Rivers. In addition to Brooks playing a dual role, the film also features Brooks regulars Dom DeLuise and Rudy De Luca in cameo appearances.
- Well-ordering theorem (Wikipedia)
In mathematics, the well-ordering theorem, also known as Zermelo’s theorem, states that every set can be well-ordered. A set X is well-ordered by a strict total order if every non-empty subset of X has a least element under the ordering. The well-ordering theorem together with Zorn’s lemma are the most important mathematical statements that are equivalent to the axiom of choice (often called AC, see also Axiom of choice § Equivalents). Ernst Zermelo introduced the axiom of choice as an “unobjectionable logical principle” to prove the well-ordering theorem. One can conclude from the well-ordering theorem that every set is susceptible to transfinite induction, which is considered by mathematicians to be a powerful technique. One famous consequence of the theorem is the Banach–Tarski paradox.