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Theorem 3anbi123d 1243
Description: Deduction joining 3 equivalences to form equivalence of conjunctions. (Contributed by NM, 22-Apr-1994.)
Hypotheses
Ref Expression
bi3d.1 (𝜑 → (𝜓𝜒))
bi3d.2 (𝜑 → (𝜃𝜏))
bi3d.3 (𝜑 → (𝜂𝜁))
Assertion
Ref Expression
3anbi123d (𝜑 → ((𝜓𝜃𝜂) ↔ (𝜒𝜏𝜁)))

Proof of Theorem 3anbi123d
StepHypRef Expression
1 bi3d.1 . . . 4 (𝜑 → (𝜓𝜒))
2 bi3d.2 . . . 4 (𝜑 → (𝜃𝜏))
31, 2anbi12d 456 . . 3 (𝜑 → ((𝜓𝜃) ↔ (𝜒𝜏)))
4 bi3d.3 . . 3 (𝜑 → (𝜂𝜁))
53, 4anbi12d 456 . 2 (𝜑 → (((𝜓𝜃) ∧ 𝜂) ↔ ((𝜒𝜏) ∧ 𝜁)))
6 df-3an 921 . 2 ((𝜓𝜃𝜂) ↔ ((𝜓𝜃) ∧ 𝜂))
7 df-3an 921 . 2 ((𝜒𝜏𝜁) ↔ ((𝜒𝜏) ∧ 𝜁))
85, 6, 73bitr4g 221 1 (𝜑 → ((𝜓𝜃𝜂) ↔ (𝜒𝜏𝜁)))
Colors of variables: wff set class
Syntax hints:  wi 4  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:  3anbi12d  1244  3anbi13d  1245  3anbi23d  1246  limeq  4132  smoeq  5928  tfrlemi1  5969  ereq1  6136  elinp  6664  iccshftr  9016  iccshftl  9018  iccdil  9020  icccntr  9022  fzaddel  9077  elfzomelpfzo  9240  divalglemnn  10318  divalglemeunn  10321  divalglemeuneg  10323  dfgcd2  10403
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