There are 68 entries in the database, listed below. Dependencies for each entry are listed in brackets. Numberings update automatically as the database is expanded.
- Terminology: Class, membership
- Terminology: Recursion, structural induction
- Terminology: Statement [1] [2]
- Definition: Conjunction [2] [3]
- Definition: Negation [3]
- Definition: Disjunction [2] [3] [4] [5]
- Definition: Implication [2] [3] [4] [5]
- Definition: Equivalence [2] [3] [4] [7]
- Definition: Existential quantification [1] [2] [3]
- Definition: Bounded existence statement [1] [3] [4] [9]
- Definition: Universal quantification [1] [2] [3] [5] [9]
- Definition: Bounded universal statement [1] [3] [7] [11]
- Definition: Occurrence of a variable [1] [2] [3] [4] [5] [9]
- Proposition: Variable occurrence in generalized conjunctions [1] [2] [3] [4] [13]
- Proposition: Variable occurrence in disjunctions [1] [3] [4] [5] [6] [13]
- Proposition: Variable occurrence in implications [1] [3] [4] [5] [7] [13]
- Proposition: Variable occurrence in equivalences [1] [3] [4] [7] [8] [13] [16]
- Proposition: Variable occurrence in generalized existence statements [1] [2] [3] [9] [13]
- Proposition: Variable occurrence in universal statements [1] [3] [5] [9] [11] [13]
- Proposition: Variable occurrence in generalized universal statements [1] [2] [3] [11] [13] [19]
- Definition: Free occurrence of a variable [1] [2] [3] [4] [5] [9] [13]
- Proposition/definition: Variable substitution [1] [2] [3] [4] [5] [9]
- Proposition: Variable substitution in disjunctions [1] [3] [4] [5] [6] [22]
- Proposition: Variable substitution in implications [1] [3] [4] [5] [7] [22]
- Proposition: Variable substitution in equivalences [1] [3] [4] [7] [8] [22] [24]
- Proposition: Variable substitution in universal statements [1] [3] [5] [9] [11] [22]
- Definition: Simple multiple variable substitution [2] [22]
- Definition: Multiple variable substitution [1] [3] [27]
- Terminology: Predicate [1] [3] [21] [28]
- Definition: Unary predicate [29]
- Definition: Set, proper class [1] [9] [30]
- Definition: Binary predicate [1] [29]
- Definition: Membership predicate [1] [29] [32]
- Definition: Conjunction of binary predicates [2] [4] [32]
- Definition: Negation of binary predicates [29] [32]
- Proposition/definition: Reverse binary predicate [29] [32]
- Definition: Equality, distinctness [1] [3] [5] [8] [12] [31] [32] [35]
- Terminology: Inference, entailment [3]
- Terminology: Inference rule [3] [38]
- Inference rule: Conjunction introduction [4] [39]
- Proposition: Generalized conjunction introduction [2] [3] [4] [39] [40]
- Inference rule: Conjunction elimination [4] [39]
- Proposition: Generalized conjunction elimination [2] [3] [4] [39] [42]
- Proposition: Idempotence of conjunction [4] [39] [40] [42]
- Proposition: Commutativity of conjunction [4] [39] [40] [42]
- Proposition: Associativity of conjunction [4] [39] [40] [42]
- Theorem: The weakening rule [4] [38] [39] [40] [42]
- Theorem: The identity rule [3] [4] [38] [39] [40] [42]
- Inference rule: Negation introduction [5] [38] [39]
- Theorem: Law of Noncontradiction [4] [5] [38] [39] [42] [49]
- Proposition: Negation of entailment [5] [38] [39] [47] [49]
- Proposition: Statements entailing their own negation [5] [38] [39] [48] [49]
- Proposition: Double negation introduction [5] [39] [47] [48] [49]
- Proposition: Double negation of entailment [5] [38] [39] [51]
- Proposition: Triple negation elimination [5] [39] [47] [49] [53]
- Inference rule: Double negation elimination [5] [39]
- Theorem: The cut rule [5] [38] [39] [47] [49] [51] [56]
- Theorem: The exchange rule [4] [38] [39] [45] [57]
- Theorem: The contraction rule [4] [38] [39] [40] [42] [57]
- Proposition: Weakening of assumption [4] [38] [39] [42] [57] [58]
- Proposition: Transitivity of entailment [38] [39] [57]
- Proposition: Double negation elimination for entailment [5] [38] [39] [53] [56] [57]
- Theorem: Negation elimination [5] [38] [39] [47] [51] [56] [62]
- Proposition: Negation elimination for entailment [5] [38] [39] [51] [62]
- Terminology: Axiom [3] [38]
- Axiom of Extensionality [1] [7] [11] [12] [31] [37] [65]
- Axiom of Pairing [6] [8] [10] [12] [31] [37] [65]
- Axiom of Difference [1] [4] [8] [9] [11] [12] [31] [35] [65]
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