Theorem pm3.22

Description: Theorem *3.22 of WhiteheadRussell p. 111. (Contributed by NM, 3-Jan-2005) (Proof shortened by Wolf Lammen, 13-Nov-2012)

	Ref	Expression
Assertion	pm3.22	$$⊢\left(\phi \wedge \psi \right)\to \left(\psi \wedge \phi \right)$$

Proof

Step	Hyp	Ref	Expression
1		id	$$⊢\left(\psi \wedge \phi \right)\to \left(\psi \wedge \phi \right)$$
2	1	ancoms	$$⊢\left(\phi \wedge \psi \right)\to \left(\psi \wedge \phi \right)$$