Theorem syl3an2b

Description: A syllogism inference. (Contributed by NM, 22-Aug-1995)

	Ref	Expression
Hypotheses	syl3an2b.1	⊢ ( 𝜑 ↔ 𝜒 )
	syl3an2b.2	⊢ ( ( 𝜓 ∧ 𝜒 ∧ 𝜃 ) → 𝜏 )
Assertion	syl3an2b	⊢ ( ( 𝜓 ∧ 𝜑 ∧ 𝜃 ) → 𝜏 )

Proof

Step	Hyp	Ref	Expression
1		syl3an2b.1	⊢ ( 𝜑 ↔ 𝜒 )
2		syl3an2b.2	⊢ ( ( 𝜓 ∧ 𝜒 ∧ 𝜃 ) → 𝜏 )
3	1	biimpi	⊢ ( 𝜑 → 𝜒 )
4	3 2	syl3an2	⊢ ( ( 𝜓 ∧ 𝜑 ∧ 𝜃 ) → 𝜏 )