## What does ZFC mean with relationship to set theory?

Zermelo–Fraenkel set theory with the axiom of choice included is abbreviated ZFC, where C stands for “choice”, and ZF refers to the axioms of Zermelo–Fraenkel set theory with the axiom of choice excluded.

## Who formulated the set theory?

Georg Cantor

Set theory, as a separate mathematical discipline, begins in the work of Georg Cantor. One might say that set theory was born in late 1873, when he made the amazing discovery that the linear continuum, that is, the real line, is not countable, meaning that its points cannot be counted using the natural numbers.

**Is ZFC complete?**

ZFC is incomplete, and so is any theory we can describe. However, there seems to be a linear ordering of strengthenings of ZFC, provided by the large cardinal axioms.

**Is ZFC a first order theory?**

ZFC is a first-order logic theory, it allows only to quantify over elements of the universe. It is also one-sorted since there is only one type of elements in a universe of ZFC, namely sets.

### Who is the father of analysis?

Karl Theodor Wilhelm Weierstrass

Karl Theodor Wilhelm Weierstrass (German: Weierstraß [ˈvaɪɐʃtʁaːs]; 31 October 1815 – 19 February 1897) was a German mathematician often cited as the “father of modern analysis”….

Karl Weierstrass | |
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Nationality | German |

Alma mater | University of Bonn Münster Academy |

### Does the empty set exist?

An empty set exists. This formula is a theorem and considered true in every version of set theory.

**Is ZF consistent?**

NO; if ZF is consistent, it has a model but this model is not a set whose existence the theory ZF can prove to exist. To prove the consistency of ZF we need a “stronger” meta-theory.

**How many axioms are in ZF?**

eight axioms

These 8 axioms define a consistent theory, ZF (though, of course, it is very difficult to prove that this system is consistent). When the axiom of choice is added to the eight axioms above, the theory becomes ZFC (the “C” for choice), and it is this system that is commonly used as the foundation of mathematics.