Theorem mp1i

Description: Inference detaching an antecedent and introducing a new one. (Contributed by Stefan O'Rear, 29-Jan-2015)

	Ref	Expression
Hypotheses	mp1i.1	⊢ 𝜑
	mp1i.2	⊢ ( 𝜑 → 𝜓 )
Assertion	mp1i	⊢ ( 𝜒 → 𝜓 )

Proof

Step	Hyp	Ref	Expression
1		mp1i.1	⊢ 𝜑
2		mp1i.2	⊢ ( 𝜑 → 𝜓 )
3	1 2	ax-mp	⊢ 𝜓
4	3	a1i	⊢ ( 𝜒 → 𝜓 )