Single Idea 9514

[catalogued under 4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / a. Symbols of PL]

Full Idea

If we say that A and B are 'interderivable' from one another (that is, A |- B and B |- A), then we may write A -||- B.

Gist of Idea

If A and B are 'interderivable' from one another we may write A -||- B

Source

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

Book Reference

Lemmon,E.J.: 'Beginning Logic' [Nelson 1979], p.34

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