Singleton
From Encyclopedia of Mathematics
2020 Mathematics Subject Classification: Primary: 03E [MSN][ZBL]
A set which contains exactly one element. Notation: $\{ x \}$. One has $y \in \{ x \} \Leftrightarrow y = x$.
References
| [1] | P. R. Halmos, Naive Set Theory, Springer (1960) ISBN 0-387-90092-6 |
How to Cite This Entry:
Singleton. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Singleton&oldid=53851
Singleton. Encyclopedia of Mathematics. URL: http://encyclopediaofmath.org/index.php?title=Singleton&oldid=53851