- Kripkean possible-worlds semantics(in philosophy of language and logic)
- A framework developed by philosopher Saul Kripke for understanding meaning and truth by imagining different possible scenarios or 'worlds' where things could be different, and checking what's true in each one.
- NP problems(in computer science)
- A broad class of difficult math and logic problems where checking a proposed solution is quick, even if finding solutions is hard.
- NP-complete problem(Computational complexity theory)
- A problem that is among the most difficult in NP, to which all other problems in NP are polynomial-time reducible, such that a polynomial time solution for any one would yield polynomial time solutions for all problems in NP.
- Polynomial algorithm(in computer science)
- A step-by-step procedure for solving a problem that doesn't take an absurdly long time—roughly, the time it takes grows at a reasonable rate as the problem gets bigger.
- Saul Kripke(in 20th-century philosophy)
- An influential modern philosopher who developed new ways of thinking about meaning, necessity, and possibility by using the idea of 'possible worlds.'
- Transferable property(in logic and reasoning)
- A characteristic that, if it's true for one thing, automatically must be true for something related to it.
- existence(Kant's analysis in the Critique of Pure Reason as applied to the ontological argument)
- Not a real predicate or positive determination; it does not add to or enlarge the concept of a subject.
- inference(Nyāya epistemology)
- A component of epistemology in Nyāya philosophy; a veritable inference yields knowledge about the world and must have premises that are themselves known
- possible worlds(Leibniz's modal semantics, anticipating contemporary possible-worlds semantics)
- Worlds that have existence in a tenuous sense; fictional worlds used to characterize the nature of possibles that are never actualized