Theorem 3anbi123i 1178

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 456	. . 3 ⊢ ((𝜑 ∧ 𝜒) ↔ (𝜓 ∧ 𝜃))
4		bi3.3	. . 3 ⊢ (𝜏 ↔ 𝜂)
5	3, 4	anbi12i 456	. 2 ⊢ (((𝜑 ∧ 𝜒) ∧ 𝜏) ↔ ((𝜓 ∧ 𝜃) ∧ 𝜂))
6		df-3an 970	. 2 ⊢ ((𝜑 ∧ 𝜒 ∧ 𝜏) ↔ ((𝜑 ∧ 𝜒) ∧ 𝜏))
7		df-3an 970	. 2 ⊢ ((𝜓 ∧ 𝜃 ∧ 𝜂) ↔ ((𝜓 ∧ 𝜃) ∧ 𝜂))
8	5, 6, 7	3bitr4i 211	1 ⊢ ((𝜑 ∧ 𝜒 ∧ 𝜏) ↔ (𝜓 ∧ 𝜃 ∧ 𝜂))

Syntax hints:   ∧ wa 103   ↔ wb 104   ∧ w3a 968

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107

This theorem depends on definitions:  df-bi 116  df-3an 970

This theorem is referenced by:  3anbi1i  1180  3anbi2i  1181  3anbi3i  1182  syl3anb  1271  ne3anior  2424  isstructim  12408