Theorem pm2.62

Description: Theorem *2.62 of WhiteheadRussell p. 107. (Contributed by NM, 3-Jan-2005) (Proof shortened by Wolf Lammen, 13-Dec-2013)

	Ref	Expression
Assertion	pm2.62	⊢ ( ( 𝜑 ∨ 𝜓 ) → ( ( 𝜑 → 𝜓 ) → 𝜓 ) )

Proof

Step	Hyp	Ref	Expression
1		pm2.621	⊢ ( ( 𝜑 → 𝜓 ) → ( ( 𝜑 ∨ 𝜓 ) → 𝜓 ) )
2	1	com12	⊢ ( ( 𝜑 ∨ 𝜓 ) → ( ( 𝜑 → 𝜓 ) → 𝜓 ) )