logicUSLIB/logicus-pl/4.2.0

LogicUS.PL.DeductionSystems

Deduction systems for propositional logic ready to use with LogicUS.PL.Deduction, as text that can be edited: rules can be removed, renamed or added before reading it with readSystem.

Presets

type alias Preset =
{ name : String
, description : String
, rules : String
}

A system with a name and a short description.

presets : List Preset

The systems of this module. LogicUS.FOL.DeductionSystems has their first-order versions, with the same names.

presetSystem : String -> Maybe System

The system of a preset, by name.

Rules

Classical natural deduction: the intuitionistic and the classical rules.

The rules of natural deduction for the connectives that hold intuitionistically (introduction and elimination of ∧, ∨, →, ↔, ¬ and ⊥), and reiteration.

The classical rules: elimination of the double negation and reduction to the absurd.

derivedRules : String

Rules that can be derived from the others, for exercises that allow them: modus tollens, disjunctive and hypothetical syllogisms, introduction of the double negation, excluded middle and De Morgan laws.

axiomatic : String

An axiomatic system (Łukasiewicz): three axiom schemes and modus ponens.