러셀의 역설

One of the logical paradoxes - a contradiction - in naive set theory, discovered by Bertrand Russell in or around 1901.

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Let $R=\{x\mid x\notin x\}$ then $R\in R⟺R\notin R$.

Articles

• plato.stanford.edu/entries/russell-paradox/
• en.wikipedia.org/wiki/Russell%27s_paradox