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Theorem 3anbi2d 1257
Description: Deduction adding conjuncts to an equivalence. (Contributed by NM, 8-Sep-2006.)
Hypothesis
Ref Expression
3anbi1d.1 (φ → (ψχ))
Assertion
Ref Expression
3anbi2d (φ → ((θ ψ τ) ↔ (θ χ τ)))

Proof of Theorem 3anbi2d
StepHypRef Expression
1 biidd 228 . 2 (φ → (θθ))
2 3anbi1d.1 . 2 (φ → (ψχ))
31, 23anbi12d 1253 1 (φ → ((θ ψ τ) ↔ (θ χ τ)))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 176   w3a 934
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 177  df-an 360  df-3an 936
This theorem is referenced by:  vtocl3gaf  2924  opkelins2kg  4252  opkelins3kg  4253  opkelsikg  4265  sikss1c1c  4268  brsi  4762  brsnsi  5774  nenpw1pwlem2  6086  ovce  6173
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