Single Idea 9401

[catalogued under 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / c. Derivation rules of PL]

Full Idea

Or-Elimination (∨E): Given A∨B, we may derive C if it is proved from A as assumption and from B as assumption. This will also depend on prior assumptions.

Clarification

∨ is 'or'

Gist of Idea

∨E: Derive C from A∨B, if C can be derived both from A and from B

Source

E.J. Lemmon (Beginning Logic [1965], 1.5)

Book Reference

Lemmon,E.J.: 'Beginning Logic' [Nelson 1979], p.40

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