Metamath Proof Explorer


Theorem pm2.27

Description: This theorem, sometimes called "Assertion" or "Pon" (for "ponens"), can be thought of as a closed form of modus ponens ax-mp . Theorem *2.27 of WhiteheadRussell p. 104. (Contributed by NM, 15-Jul-1993)

Ref Expression
Assertion pm2.27 φ φ ψ ψ

Proof

Step Hyp Ref Expression
1 id φ ψ φ ψ
2 1 com12 φ φ ψ ψ