/explore

Click through on any links that interest you or select the planets on the right to continue exploring the Outer Web.
You are here

xorshammer.com
| | www.logicmatters.net

A standard menu for a first mathematical logic course might be something like this: (1) A treatment of the syntax and semantics of FOL, presenting a proof system or two, leading up to a proof of a Gödel's completeness theorem (and then a glance at e.g. the compactness theorem and some initial implications). (2) An [...]
3.0 parsecs

Travel
| |
| | nickdrozd.github.io

Goedel's first incompleteness theorem is the claim that any sound, consistent formal system of sufficient power is incomplete; that is, there are statements in the language of the system that can neither be proved nor disproved. Traditionally the theorem is proved by exhbiting a statement g which is provably equivalent to a statement encoding its own disprovability in the system S.
3.2 parsecs

Travel
| |
| | unstableontology.com

(note: one may find the embedded LaTeX more readable on LessWrong) The Löwenheim-Skolem theorem implies, among other things, that any first-order theory whose symbols are countable, and which has an infinite model, has a countably infinite model. This means that, in attempting to refer to uncountably infinite structures (such as in set theory), one "may...
3.0 parsecs

Travel
| |
| | reasonableapproximation.net


29.7 parsecs

Travel
|