more from E.J. Lemmon

Single Idea 9393

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

Full Idea

Assumptions (A): any proposition may be introduced at any stage of a proof.

Gist of Idea

A: we may assume any proposition at any stage

Source

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

Book Reference

Lemmon,E.J.: 'Beginning Logic' [Nelson 1979], p.39