Theorem imbitrid

Description: A mixed syllogism inference. (Contributed by NM, 12-Jan-1993)

	Ref	Expression
Hypotheses	imbitrid.1	⊢ ( 𝜑 → 𝜓 )
	imbitrid.2	⊢ ( 𝜒 → ( 𝜓 ↔ 𝜃 ) )
Assertion	imbitrid	⊢ ( 𝜒 → ( 𝜑 → 𝜃 ) )

Proof

Step	Hyp	Ref	Expression
1		imbitrid.1	⊢ ( 𝜑 → 𝜓 )
2		imbitrid.2	⊢ ( 𝜒 → ( 𝜓 ↔ 𝜃 ) )
3	2	biimpd	⊢ ( 𝜒 → ( 𝜓 → 𝜃 ) )
4	1 3	syl5	⊢ ( 𝜒 → ( 𝜑 → 𝜃 ) )