1. Lean4 Logic Formalization
  2. 1. Usage
  3. 2. Contributing
  4. 3. References and Related Works
  5. Preliminaries
  6. 4. Definitions and Notations
  7. 5. Computability
  8. Classical Logics
  9. 6. Classical Propositional Logic
    1. 6.1. Syntax and Semantics
  10. 7. First-Order Logic
    1. 7.1. Term and Formula
      1. 7.1.1. Binder Notation
    2. 7.2. Deduction System
    3. 7.3. Semantics
    4. 7.4. Completeness
    5. 7.5. Arithmetics
      1. 7.5.1. Theories of Arithmetics
      2. 7.5.2. Theory IΣ₀
      3. 7.5.3. Theory IΣ₁
      4. 7.5.4. Gödel's First Incompleteness Theorem
      5. 7.5.5. Gödel's Second Incompleteness Theorem
    6. 7.6. Interpretation
  11. Non-Classical Logics
  12. 8. Superintuitionistic Propositional Logic
    1. 8.1. Axioms
    2. 8.2. Deduction
      1. 8.2.1. Glivenko's Theorem
    3. 8.3. Kripke Semantics
      1. 8.3.1. Soundness
      2. 8.3.2. Completeness
    4. 8.4. Rejection Law of Excluded Middle
    5. 8.5. Disjunctive Property
  13. 9. Standard Modal Logic
    1. 9.1. Axioms
    2. 9.2. Deduction
    3. 9.3. Kripke Semantics
      1. 9.3.1. Soundness
      2. 9.3.2. Completeness
    4. 9.4. On GL
      1. 9.4.1. Frame Definability
    5. 9.5. Strengh between Logics
    6. 9.6. Undefinability of Frame Property
    7. 9.7. Modal Companion

Logic Formalization in Lean 4

Term and Formula