Order Theory
The answer to Suslin's problem is independent of ZFC. The diamond principle ◊ proves the existence of a Suslin line, while MA + ¬CH proves that no Suslin line exists.
Existence of Kurepa trees is independent of ZFC.
Read more about this topic: List Of Statements Undecidable In ZFC
Famous quotes containing the words order and/or theory:
“It is the international system of currency which determines the totality of life on this planet. That is the natural order of things today. That is the atomic, and sub-atomic, and galactic
structure of things today. And you have meddled with the primal forces of nature! And you will atone! Am I getting through to you, Mr. Beale?”
—Paddy Chayefsky (1923–1981)
“... the first reason for psychology’s failure to understand what people are and how they act, is that clinicians and psychiatrists, who are generally the theoreticians on these matters, have essentially made up myths without any evidence to support them; the second reason for psychology’s failure is that personality theory has looked for inner traits when it should have been looking for social context.”
—Naomi Weisstein (b. 1939)