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Everything about Consistency

Non-contradiction of a theory

In deductive logic, a consistent theory is one that does not lead to a logical contradiction. A theory is consistent if there is no formula such that both and its negation are elements of the set of consequences of. Let be a set of closed sentences and the set of closed sentences provable from under some formal deductive system. The set of axioms is consistent when there is no formula such that and. A trivial theory is clearly inconsistent. Conversely, in an explosive formal system every inconsistent theory is trivial. Consistency of a theory is a syntactic notion, whose semantic counterpart is satisfiability. A theory is satisfiable if it has a model, i.e., there exists an interpretation under which all axioms in the theory are true. This is what consistent meant in traditional Aristotelian logic, although in contemporary mathematical logic the term satisfiable is used instead. Wikipedia →

🧭 Start here: a 6-step reading path

  1. Read the overview: ConsistencyA 5-minute orientation
  2. Skim a recent paper: Interpolation consistency training for semi-supervised learningInfluential work since 2022
  3. Pick up a classic book: Theological IncorrectnessThe most-reprinted book on the subject
  4. Read the landmark paper: The Columbia–Suicide Severity Rating Scale: Initial Validity and Internal Consistency Findings From Three Multisite Studies With Adolescents and AdultsCited 4,822 times
  5. Go sideways: Gödel's completeness theoremA closely related topic
  6. Go sideways: Theory (mathematical logic)A closely related topic

📖 Definitions

Noun Local coherence.

Noun Correspondence or compatibility.

Noun Reliability or uniformity; the quality of being consistent.

Noun The degree of viscosity of something.

🏆 Landmark papers (most cited)

🆕 Influential since 2022

📚 Books worth reading

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