### Ernst Friedrich Ferdinand Zermelo

Born: 1871-07-27 in Berlin

Died: 1953-05-21 in Freiburg im Breisgau

Mathematician who did research in:

Significant work:

An modification of his axiomatic system, called Zermelo-Fraenkel, is still the most widely used such system today. Zermelo's original axioms:

**Axiom of Extensionality**
- Axiom of Elementary Sets
- Axiom of Separation
**Power Set Axiom**
**Union Axiom**
- Axiom of Choice
**Axiom of Infinity**

ZF's axioms:

**Axiom of Extensionality**
**Power Set Axiom**
**Union Axiom**
**Axiom of Infinity**
- Foundation Axiom
- Selection Axiom

Sources:

- Omega Help Index:
`http://www.ags.uni-sb.de/~omega/omegaindex/theories/zermelo-fraenkel.html`
- MacTutor History of Mathematics:
`http://www-history.mcs.st-andrews.ac.uk/history/Mathematicians/Zermelo.html`