Theorem 3anbi123i 1127

Description: Join 3 biconditionals with conjunction. (Contributed by NM, 21-Apr-1994.)

Hypotheses

Ref	Expression
bi3.1	⊢ (𝜑 ↔ 𝜓)
bi3.2	⊢ (𝜒 ↔ 𝜃)
bi3.3	⊢ (𝜏 ↔ 𝜂)

Assertion

Ref	Expression
3anbi123i	⊢ ((𝜑 ∧ 𝜒 ∧ 𝜏) ↔ (𝜓 ∧ 𝜃 ∧ 𝜂))

Proof of Theorem 3anbi123i

Step	Hyp	Ref	Expression
1		bi3.1	. . . 4 ⊢ (𝜑 ↔ 𝜓)
2		bi3.2	. . . 4 ⊢ (𝜒 ↔ 𝜃)
3	1, 2	anbi12i 447	. . 3 ⊢ ((𝜑 ∧ 𝜒) ↔ (𝜓 ∧ 𝜃))
4		bi3.3	. . 3 ⊢ (𝜏 ↔ 𝜂)
5	3, 4	anbi12i 447	. 2 ⊢ (((𝜑 ∧ 𝜒) ∧ 𝜏) ↔ ((𝜓 ∧ 𝜃) ∧ 𝜂))
6		df-3an 921	. 2 ⊢ ((𝜑 ∧ 𝜒 ∧ 𝜏) ↔ ((𝜑 ∧ 𝜒) ∧ 𝜏))
7		df-3an 921	. 2 ⊢ ((𝜓 ∧ 𝜃 ∧ 𝜂) ↔ ((𝜓 ∧ 𝜃) ∧ 𝜂))
8	5, 6, 7	3bitr4i 210	1 ⊢ ((𝜑 ∧ 𝜒 ∧ 𝜏) ↔ (𝜓 ∧ 𝜃 ∧ 𝜂))

Syntax hints:   ∧ wa 102   ↔ wb 103   ∧ w3a 919

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106

This theorem depends on definitions:  df-bi 115  df-3an 921

This theorem is referenced by:  3anbi1i  1129  3anbi2i  1130  3anbi3i  1131  syl3anb  1212  ne3anior  2333