The Logic Book

The logical system of Bergman, Moor and Nelson's "The Logic Book". We have included only Fitch derivations to match the original system.

Constants

~&∨⊃≡∀∃=

Example Formula

(∀x)(∀y)(x=y⊃(Lx≡Ly))

Term Extensions

F'a''x'''

Allow Open Sentences

No

Known Issues

* Error message terminology has not yet been customized for this system.

Problem Types

Point And Click DerivationExperimental Point And Click TableauExperimental Free Tableau

Derivation Rules

Point And Click

A: AssumptionR: Reiteration&E: Conjunction Elimination&I: Conjunction Introduction∨E: Disjunction Elimination∨I: Disjunction Introduction⊃E: Conditional Elimination⊃I: Conditional Introduction≡E: Biconditional Elimination≡I: Biconditional Introduction~I: Negation Introduction~E: Negation Elimination∃E: Existential Elimination∃I: Existential Introduction∀E: Universal Elimination∀I: Universal Introduction=E: Identity Elimination=I: Identity IntroductionMT: Modus TollensImpl: ImplicationHS: Hypothetical SyllogismDS: Disjunctive SyllogismCom: CommutationAssoc: AssociationDN: Double NegationDeM: De MorganIdem: IdempotenceTrans: TranspositionExp: ExportationDist: DistributionEquiv: EquivalenceQN: Quantifier Negation