Theorem pm5.11

Description: Theorem *5.11 of WhiteheadRussell p. 123. (Contributed by NM, 3-Jan-2005)

	Ref	Expression
Assertion	pm5.11	$$⊢\left(\left(\phi \to \psi \right)\vee \left(\neg \phi \to \psi \right)\right)$$

Proof

Step	Hyp	Ref	Expression
1		pm5.11g	$$⊢\left(\left(\phi \to \psi \right)\vee \left(\neg \phi \to \psi \right)\right)$$