Theorem pm2.61d1

Description: Inference eliminating an antecedent. (Contributed by NM, 15-Jul-2005)

	Ref	Expression
Hypotheses	pm2.61d1.1	⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) )
	pm2.61d1.2	⊢ ( ¬ 𝜓 → 𝜒 )
Assertion	pm2.61d1	⊢ ( 𝜑 → 𝜒 )

Proof

Step	Hyp	Ref	Expression
1		pm2.61d1.1	⊢ ( 𝜑 → ( 𝜓 → 𝜒 ) )
2		pm2.61d1.2	⊢ ( ¬ 𝜓 → 𝜒 )
3	2	a1i	⊢ ( 𝜑 → ( ¬ 𝜓 → 𝜒 ) )
4	1 3	pm2.61d	⊢ ( 𝜑 → 𝜒 )