Theorem a1i13

Description: Add two antecedents to a wff. (Contributed by Jeff Hankins, 4-Aug-2009)

	Ref	Expression
Hypothesis	a1i13.1	⊢ ( 𝜓 → 𝜃 )
Assertion	a1i13	⊢ ( 𝜑 → ( 𝜓 → ( 𝜒 → 𝜃 ) ) )

Proof

Step	Hyp	Ref	Expression
1		a1i13.1	⊢ ( 𝜓 → 𝜃 )
2	1	a1d	⊢ ( 𝜓 → ( 𝜒 → 𝜃 ) )
3	2	a1i	⊢ ( 𝜑 → ( 𝜓 → ( 𝜒 → 𝜃 ) ) )