back to ideas for this text

---

Single Idea 9514

[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 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

---