Propositional calculus | Theorems in propositional logic

Nicod's axiom

In logic, Nicod's axiom (named after the French logician and philosopher Jean Nicod) is a formula that can be used as the sole axiom of a semantically complete system of propositional calculus. The only connective used in the formulation of Nicod's axiom is the Sheffer's stroke. The axiom has the following form: ((φ | (χ | ψ)) | ((τ | (τ | τ)) | ((θ | χ) | ((φ | θ) | (φ | θ))))) Nicod showed that the whole propositional logic of Principia Mathematica could be derived from this axiom alone by using one inference rule, called "Nicod's modus ponens": 1. φ 2. (φ | (χ | ψ)) ∴ ψ In 1931, the Polish logician discovered an equally powerful and easier-to-work-with alternative: ((φ | (ψ | χ)) | (((τ | χ) | ((φ | τ) | (φ | τ))) | (φ | (φ | ψ)))) (Wikipedia).

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From playlist Something you did not know...

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From playlist Zermelo Fraenkel axioms

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From playlist Zermelo Fraenkel axioms

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From playlist Logic

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From playlist Theory of numbers

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From playlist Axiomatic Set Theory

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From playlist The Coordinate Plane, Plotting Points, and Solutions to Linear Equations in Two Variables

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From playlist Axiomatic Set Theory

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From playlist Zermelo Fraenkel axioms

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From playlist Fundamentals of Mathematics

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From playlist Set Theory by Mathoma

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From playlist Topology Without Tears

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From playlist Real Analysis

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From playlist Science and Research Livestreams

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From playlist Summer of Math Exposition Youtube Videos

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From playlist Zermelo Fraenkel axioms

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From playlist Zermelo Fraenkel axioms

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From playlist Algebra

Related pages

Propositional calculus | Completeness (logic) | Axiom | Principia Mathematica | Logical connective