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Theorem sbcbi2 3470
 Description: Substituting into equivalent wff's gives equivalent results. (Contributed by Giovanni Mascellani, 9-Apr-2018.)
Assertion
Ref Expression
sbcbi2 (∀𝑥(𝜑𝜓) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜓))

Proof of Theorem sbcbi2
StepHypRef Expression
1 abbi 2734 . . 3 (∀𝑥(𝜑𝜓) ↔ {𝑥𝜑} = {𝑥𝜓})
2 eleq2 2687 . . 3 ({𝑥𝜑} = {𝑥𝜓} → (𝐴 ∈ {𝑥𝜑} ↔ 𝐴 ∈ {𝑥𝜓}))
31, 2sylbi 207 . 2 (∀𝑥(𝜑𝜓) → (𝐴 ∈ {𝑥𝜑} ↔ 𝐴 ∈ {𝑥𝜓}))
4 df-sbc 3422 . 2 ([𝐴 / 𝑥]𝜑𝐴 ∈ {𝑥𝜑})
5 df-sbc 3422 . 2 ([𝐴 / 𝑥]𝜓𝐴 ∈ {𝑥𝜓})
63, 4, 53bitr4g 303 1 (∀𝑥(𝜑𝜓) → ([𝐴 / 𝑥]𝜑[𝐴 / 𝑥]𝜓))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ↔ wb 196  ∀wal 1478   = wceq 1480   ∈ wcel 1987  {cab 2607  [wsbc 3421 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1719  ax-4 1734  ax-5 1836  ax-6 1885  ax-7 1932  ax-9 1996  ax-10 2016  ax-11 2031  ax-12 2044  ax-13 2245  ax-ext 2601 This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-tru 1483  df-ex 1702  df-nf 1707  df-sb 1878  df-clab 2608  df-cleq 2614  df-clel 2617  df-sbc 3422 This theorem is referenced by:  csbeq2  3522
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