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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 → (ψ ↔ χ))
Assertion
Ref Expression
3anbi2d ⊢ (φ → ((θ ∧ ψ ∧ τ) ↔ (θ ∧ χ ∧ τ)))

Proof of Theorem 3anbi2d
StepHypRef Expression
1 biidd 228 . 2 ⊢ (φ → (θ ↔ θ))
2 3anbi1d.1 . 2 ⊢ (φ → (ψ ↔ χ))
31, 23anbi12d 1253 1 ⊢ (φ → ((θ ∧ ψ ∧ τ) ↔ (θ ∧ χ ∧ τ)))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:   → wi 4   ↔ wb 176   ∧ w3a 934
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This proof depends on definitions:  df-bi 177  df-an 360  df-3an 936
This theorem is used by:  vtocl3gaf  2924  opkelins2kg  4252  opkelins3kg  4253  opkelsikg  4265  sikss1c1c  4268  brsi  4762  brsnsi  5774  nenpw1pwlem2  6086  ovce  6173
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