ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  vtoclgaf GIF version

Theorem vtoclgaf 2817
Description: Implicit substitution of a class for a setvar variable. (Contributed by NM, 17-Feb-2006.) (Revised by Mario Carneiro, 10-Oct-2016.)
Hypotheses
Ref Expression
vtoclgaf.1 𝑥𝐴
vtoclgaf.2 𝑥𝜓
vtoclgaf.3 (𝑥 = 𝐴 → (𝜑𝜓))
vtoclgaf.4 (𝑥𝐵𝜑)
Assertion
Ref Expression
vtoclgaf (𝐴𝐵𝜓)
Distinct variable group:   𝑥,𝐵
Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑥)   𝐴(𝑥)

Proof of Theorem vtoclgaf
StepHypRef Expression
1 vtoclgaf.1 . . 3 𝑥𝐴
21nfel1 2343 . . . 4 𝑥 𝐴𝐵
3 vtoclgaf.2 . . . 4 𝑥𝜓
42, 3nfim 1583 . . 3 𝑥(𝐴𝐵𝜓)
5 eleq1 2252 . . . 4 (𝑥 = 𝐴 → (𝑥𝐵𝐴𝐵))
6 vtoclgaf.3 . . . 4 (𝑥 = 𝐴 → (𝜑𝜓))
75, 6imbi12d 234 . . 3 (𝑥 = 𝐴 → ((𝑥𝐵𝜑) ↔ (𝐴𝐵𝜓)))
8 vtoclgaf.4 . . 3 (𝑥𝐵𝜑)
91, 4, 7, 8vtoclgf 2810 . 2 (𝐴𝐵 → (𝐴𝐵𝜓))
109pm2.43i 49 1 (𝐴𝐵𝜓)
Colors of variables: wff set class
Syntax hints:  wi 4  wb 105   = wceq 1364  wnf 1471  wcel 2160  wnfc 2319
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2171
This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1472  df-sb 1774  df-clab 2176  df-cleq 2182  df-clel 2185  df-nfc 2321  df-v 2754
This theorem is referenced by:  vtoclga  2818  ssiun2s  3945  tfis  4600  fvmptf  5629  fmptco  5703  prmind2  12152
  Copyright terms: Public domain W3C validator