# Maths/Logic

### From Lesswrongwiki

Math and logic are deductive systems, where the conclusion of a successful argument follows necessarily from its premises, given the axioms of the system you’re using: number theory, geometry, predicate logic, etc.

## Blog posts

- Proofs, Implications, and Models
- Logical Pinpointing
- Standard and Nonstandard Numbers
- Gödel's Completeness and Incompleteness Theorems
- Second-Order Logic: The Controversy

## See also

- Valid argument - An argument is valid when it contains no logical fallacies
- Sound argument - an argument that is valid and whose premises are all true. In other words, the premises are true and the conclusion necessarily follows from them, making the conclusion true as well.