back to ideas for this text


Single Idea 9400

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

Full Idea

Or-Introduction (∨I): Given either A or B separately, we may derive A∨B as conclusion. This depends on the assumption of the premisses.

Clarification

∨ is 'or'

Gist of Idea

∨I: Given either A or B separately, we may derive A∨B

Source

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

Book Reference

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