Users' Mathboxes Mathbox for Giovanni Mascellani < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  sbcni Structured version   Visualization version   GIF version

Theorem sbcni 38073
Description: Move class substitution inside a negation, in inference form. (Contributed by Giovanni Mascellani, 27-May-2019.)
Hypotheses
Ref Expression
sbcni.1 𝐴 ∈ V
sbcni.2 ([𝐴 / 𝑥]𝜑𝜓)
Assertion
Ref Expression
sbcni ([𝐴 / 𝑥] ¬ 𝜑 ↔ ¬ 𝜓)

Proof of Theorem sbcni
StepHypRef Expression
1 sbcni.1 . . 3 𝐴 ∈ V
2 sbcng 3855 . . 3 (𝐴 ∈ V → ([𝐴 / 𝑥] ¬ 𝜑 ↔ ¬ [𝐴 / 𝑥]𝜑))
31, 2ax-mp 5 . 2 ([𝐴 / 𝑥] ¬ 𝜑 ↔ ¬ [𝐴 / 𝑥]𝜑)
4 sbcni.2 . 2 ([𝐴 / 𝑥]𝜑𝜓)
53, 4xchbinx 334 1 ([𝐴 / 𝑥] ¬ 𝜑 ↔ ¬ 𝜓)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wb 206  wcel 2108  Vcvv 3488  [wsbc 3804
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1793  ax-4 1807  ax-5 1909  ax-6 1967  ax-7 2007  ax-8 2110  ax-9 2118  ax-10 2141  ax-12 2178  ax-ext 2711
This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1540  df-ex 1778  df-nf 1782  df-sb 2065  df-clab 2718  df-cleq 2732  df-clel 2819  df-sbc 3805
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator