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
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“Humility is often merely feigned submissiveness assumed in order to subject others, an artifice of pride which stoops to conquer, and although pride has a thousand ways of transforming itself it is never so well disguised and able to take people in as when masquerading as humility.”
—François, Duc De La Rochefoucauld (1613–1680)
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