[{"n": "Naive set theory", "u": "/e/set-theory-and-logic/naive-set-theory/", "s": "Informal set theory foundational to modern mathematics."}, {"n": "Natural transformation", "u": "/e/set-theory-and-logic/natural-transformation/", "s": "A morphism of functors preserving categorical structure."}, {"n": "Negation", "u": "/e/set-theory-and-logic/negation/", "s": "Logical operation that inverts the truth value of a proposition."}, {"n": "New Foundations", "u": "/e/set-theory-and-logic/new-foundations/", "s": "A non-well-founded set theory conceived by Quine."}, {"n": "Operation (mathematics)", "u": "/e/set-theory-and-logic/operation-mathematics/", "s": "A function combining elements of a set into another element."}, {"n": "Ordered pair", "u": "/e/set-theory-and-logic/ordered-pair/", "s": "Ordered pair: a fundamental mathematical object with order significance."}, {"n": "Partition of a set", "u": "/e/set-theory-and-logic/partition-of-a-set/", "s": "Grouping elements into non-empty, disjoint subsets that cover the whole set."}, {"n": "Power set", "u": "/e/set-theory-and-logic/power-set/", "s": "The set of all subsets of a given set."}, {"n": "Principle of explosion", "u": "/e/set-theory-and-logic/principle-of-explosion/", "s": "From a contradiction, any proposition can be inferred."}, {"n": "Proof theory", "u": "/e/set-theory-and-logic/proof-theory/", "s": "Proofs as formal objects analyzed by mathematical techniques."}, {"n": "Propositional logic", "u": "/e/set-theory-and-logic/propositional-logic/", "s": "Branch of classical logic dealing with propositions and logical connectives."}, {"n": "Quantifier (logic)", "u": "/e/set-theory-and-logic/quantifier-logic/", "s": "Operators specifying how many individuals satisfy a property."}, {"n": "Quantifier elimination", "u": "/e/set-theory-and-logic/quantifier-elimination/", "s": "Quantifier elimination is a concept of simplification used in mathematical logic, model theory, and theoretica"}, {"n": "Recursion", "u": "/e/set-theory-and-logic/recursion/", "s": "A process defined by reference to a simpler version of itself."}, {"n": "Reductio ad absurdum", "u": "/e/set-theory-and-logic/reductio-ad-absurdum/", "s": "Proof by contradiction: one of a mathematician's finest weapons."}, {"n": "Reflexive relation", "u": "/e/set-theory-and-logic/reflexive-relation/", "s": "A binary relation where every element relates to itself."}, {"n": "Rice's theorem", "u": "/e/set-theory-and-logic/rice-s-theorem/", "s": "All non-trivial semantic properties of programs are undecidable."}, {"n": "Rule of inference", "u": "/e/set-theory-and-logic/rule-of-inference/", "s": "Norms for deriving conclusions from premises in deductive logic."}, {"n": "Russell's paradox", "u": "/e/set-theory-and-logic/russell-s-paradox/", "s": "A set-theoretic paradox showing that unrestricted comprehension leads to contradictions."}]