Löb's paradox, a puzzle in modal logic, questions the formalization of provability within a system. It leads to counterintuitive results…
A liar sentence asserts its own falsity, like 'This sentence is false.' It forms the core of the liar paradox,…
The liar paradox is a self-referential statement that asserts its own falsity. If true, it must be false; if false,…
Leibniz's Law, also known as the principle of the identity of indiscernibles, posits that if two entities share precisely the…
A cornerstone of classical logic, the law of non-contradiction asserts that a statement and its negation cannot both be true…
A formal framework for modal logic using possible worlds. Developed by Saul Kripke, it enables rigorous analysis of necessity, possibility,…
A logic designed for higher-order quantification and modalities. It emerged from discussions on the foundations of mathematics by Kreisel and…
A paradox in epistemic logic concerning self-reference, where a statement claims its own unprovability or unknowability, leading to logical contradictions.
A paradox where the truth of a statement implies its knowability. This epistemic puzzle, particularly in modal logic, raises questions…
Explore Stephen Cole Kleene's three-valued logic system, K3. It introduces an 'undefined' truth value alongside true and false, offering a…