Theorem pm5.14

Description: Theorem *5.14 of WhiteheadRussell p. 123. (Contributed by NM, 3-Jan-2005)

	Ref	Expression
Assertion	pm5.14	⊢ ( ( 𝜑 → 𝜓 ) ∨ ( 𝜓 → 𝜒 ) )

Proof

Step	Hyp	Ref	Expression
1		pm2.521g	⊢ ( ¬ ( 𝜑 → 𝜓 ) → ( 𝜓 → 𝜒 ) )
2	1	orri	⊢ ( ( 𝜑 → 𝜓 ) ∨ ( 𝜓 → 𝜒 ) )