# Gödel's incompleteness theorems

Gödel's incompleteness theorems is the name given to two theorems (true mathematical statements), proved by Kurt Gödel in 1931. They are theorems in mathematical logic.

Mathematicians once thought that everything that is true has a mathematical proof. A system that has this property is called complete; one that does not is called incomplete. Also, mathematical ideas should not have contradictions. This means that they should not be true and false at the same time. A system that does not include contradictions is called consistent.

Gödel said that every non-trivial (interesting) formal system is either incomplete or inconsistent: [1]

1. There will always be questions that cannot be answered, using a certain set of axioms;
2. You cannot prove that a system of axioms is consistent, unless you use a different set of axioms .

Those theorems are important to mathematicians because they prove that is impossible to create a set of axioms that explains everything in math.

## References

1. Nagel, Ernest; Newman, James Roy & Hofstadter, Douglas [1958] 2002. Gödel's proof, revised ed. ISBN 0-8147-5816-9 [1]