A theory is a set of sentences which is closed under logical implication. That is, given any subset of sentences in the theory, if sentence is a logical consequence of , then must also be in the theory.

# Theory

## See also

Logic, Sentence## Explore with Wolfram|Alpha

## References

Enderton, H. B.*Elements of Set Theory.*New York: Academic Press, 1977.

## Referenced on Wolfram|Alpha

Theory## Cite this as:

Weisstein, Eric W. "Theory." From *MathWorld*--A
Wolfram Web Resource. https://mathworld.wolfram.com/Theory.html