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Single Idea 9510

[from 'Beginning Logic' by E.J. Lemmon, in 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL ]

Full Idea

If P and Q are any two propositions, the proposition that either P or Q is called the 'disjunction' of P and Q, and is written P∨Q.

Gist of Idea

That proposition that either P or Q is their 'disjunction', written P∨Q

Source

E.J. Lemmon (Beginning Logic [1965], 1.3)

Book Reference

Lemmon,E.J.: 'Beginning Logic' [Nelson 1979], p.19


A Reaction

This is inclusive-or (meaning 'P, or Q, or both'), and not exlusive-or (Boolean XOR), which means 'P, or Q, but not both'. The ∨ sign is sometimes called 'vel' (Latin).