Users' Mathboxes Mathbox for Andrew Salmon < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  pm13.194 Structured version   Visualization version   GIF version

Theorem pm13.194 41919
Description: Theorem *13.194 in [WhiteheadRussell] p. 179. (Contributed by Andrew Salmon, 3-Jun-2011.)
Assertion
Ref Expression
pm13.194 ((𝜑𝑥 = 𝑦) ↔ ([𝑦 / 𝑥]𝜑𝜑𝑥 = 𝑦))

Proof of Theorem pm13.194
StepHypRef Expression
1 pm13.13a 41914 . . . 4 ((𝜑𝑥 = 𝑦) → [𝑦 / 𝑥]𝜑)
2 sbsbc 3715 . . . 4 ([𝑦 / 𝑥]𝜑[𝑦 / 𝑥]𝜑)
31, 2sylibr 233 . . 3 ((𝜑𝑥 = 𝑦) → [𝑦 / 𝑥]𝜑)
4 simpl 482 . . 3 ((𝜑𝑥 = 𝑦) → 𝜑)
5 simpr 484 . . 3 ((𝜑𝑥 = 𝑦) → 𝑥 = 𝑦)
63, 4, 53jca 1126 . 2 ((𝜑𝑥 = 𝑦) → ([𝑦 / 𝑥]𝜑𝜑𝑥 = 𝑦))
7 3simpc 1148 . 2 (([𝑦 / 𝑥]𝜑𝜑𝑥 = 𝑦) → (𝜑𝑥 = 𝑦))
86, 7impbii 208 1 ((𝜑𝑥 = 𝑦) ↔ ([𝑦 / 𝑥]𝜑𝜑𝑥 = 𝑦))
Colors of variables: wff setvar class
Syntax hints:  wb 205  wa 395  w3a 1085  [wsb 2068  [wsbc 3711
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1799  ax-4 1813  ax-5 1914  ax-6 1972  ax-7 2012  ax-8 2110  ax-9 2118  ax-12 2173  ax-ext 2709
This theorem depends on definitions:  df-bi 206  df-an 396  df-3an 1087  df-ex 1784  df-sb 2069  df-clab 2716  df-cleq 2730  df-clel 2817  df-sbc 3712
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator