Theorem 3orbi123d 1431

Description: Deduction joining 3 equivalences to form equivalence of disjunctions. (Contributed by NM, 20-Apr-1994.)

Hypotheses

Ref	Expression
bi3d.1	⊢ (𝜑 → (𝜓 ↔ 𝜒))
bi3d.2	⊢ (𝜑 → (𝜃 ↔ 𝜏))
bi3d.3	⊢ (𝜑 → (𝜂 ↔ 𝜁))

Assertion

Ref	Expression
3orbi123d	⊢ (𝜑 → ((𝜓 ∨ 𝜃 ∨ 𝜂) ↔ (𝜒 ∨ 𝜏 ∨ 𝜁)))

Proof of Theorem 3orbi123d

Step	Hyp	Ref	Expression
1		bi3d.1	. . . 4 ⊢ (𝜑 → (𝜓 ↔ 𝜒))
2		bi3d.2	. . . 4 ⊢ (𝜑 → (𝜃 ↔ 𝜏))
3	1, 2	orbi12d 915	. . 3 ⊢ (𝜑 → ((𝜓 ∨ 𝜃) ↔ (𝜒 ∨ 𝜏)))
4		bi3d.3	. . 3 ⊢ (𝜑 → (𝜂 ↔ 𝜁))
5	3, 4	orbi12d 915	. 2 ⊢ (𝜑 → (((𝜓 ∨ 𝜃) ∨ 𝜂) ↔ ((𝜒 ∨ 𝜏) ∨ 𝜁)))
6		df-3or 1084	. 2 ⊢ ((𝜓 ∨ 𝜃 ∨ 𝜂) ↔ ((𝜓 ∨ 𝜃) ∨ 𝜂))
7		df-3or 1084	. 2 ⊢ ((𝜒 ∨ 𝜏 ∨ 𝜁) ↔ ((𝜒 ∨ 𝜏) ∨ 𝜁))
8	5, 6, 7	3bitr4g 316	1 ⊢ (𝜑 → ((𝜓 ∨ 𝜃 ∨ 𝜂) ↔ (𝜒 ∨ 𝜏 ∨ 𝜁)))

Syntax hints:   → wi 4   ↔ wb 208   ∨ wo 843   ∨ w3o 1082

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 209  df-or 844  df-3or 1084

This theorem is referenced by:  moeq3  3703  soeq1  5489  solin  5493  soinxp  5628  ordtri3or  6218  isosolem  7094  sorpssi  7449  dfwe2  7490  f1oweALT  7667  soxp  7817  elfiun  8888  sornom  9693  ltsopr  10448  elz  11977  dyaddisj  24191  istrkgl  26238  istrkgld  26239  axtgupdim2  26251  tgdim01  26287  tglngval  26331  tgellng  26333  colcom  26338  colrot1  26339  legso  26379  lncom  26402  lnrot1  26403  lnrot2  26404  ttgval  26655  colinearalg  26690  axlowdim2  26740  axlowdim  26741  elntg  26764  elntg2  26765  nb3grprlem2  27157  frgrwopreg  28096  istrkg2d  31932  axtgupdim2ALTV  31934  brcolinear2  33514  colineardim1  33517  colinearperm1  33518  fin2so  34873  uneqsn  40366  3orbi123  40838