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Theorem cbvrab 2710
 Description: Rule to change the bound variable in a restricted class abstraction, using implicit substitution. This version has bound-variable hypotheses in place of distinct variable conditions. (Contributed by Andrew Salmon, 11-Jul-2011.) (Revised by Mario Carneiro, 9-Oct-2016.)
Hypotheses
Ref Expression
cbvrab.1 𝑥𝐴
cbvrab.2 𝑦𝐴
cbvrab.3 𝑦𝜑
cbvrab.4 𝑥𝜓
cbvrab.5 (𝑥 = 𝑦 → (𝜑𝜓))
Assertion
Ref Expression
cbvrab {𝑥𝐴𝜑} = {𝑦𝐴𝜓}

Proof of Theorem cbvrab
Dummy variable 𝑧 is distinct from all other variables.
StepHypRef Expression
1 nfv 1508 . . . 4 𝑧(𝑥𝐴𝜑)
2 cbvrab.1 . . . . . 6 𝑥𝐴
32nfcri 2293 . . . . 5 𝑥 𝑧𝐴
4 nfs1v 1919 . . . . 5 𝑥[𝑧 / 𝑥]𝜑
53, 4nfan 1545 . . . 4 𝑥(𝑧𝐴 ∧ [𝑧 / 𝑥]𝜑)
6 eleq1 2220 . . . . 5 (𝑥 = 𝑧 → (𝑥𝐴𝑧𝐴))
7 sbequ12 1751 . . . . 5 (𝑥 = 𝑧 → (𝜑 ↔ [𝑧 / 𝑥]𝜑))
86, 7anbi12d 465 . . . 4 (𝑥 = 𝑧 → ((𝑥𝐴𝜑) ↔ (𝑧𝐴 ∧ [𝑧 / 𝑥]𝜑)))
91, 5, 8cbvab 2281 . . 3 {𝑥 ∣ (𝑥𝐴𝜑)} = {𝑧 ∣ (𝑧𝐴 ∧ [𝑧 / 𝑥]𝜑)}
10 cbvrab.2 . . . . . 6 𝑦𝐴
1110nfcri 2293 . . . . 5 𝑦 𝑧𝐴
12 cbvrab.3 . . . . . 6 𝑦𝜑
1312nfsb 1926 . . . . 5 𝑦[𝑧 / 𝑥]𝜑
1411, 13nfan 1545 . . . 4 𝑦(𝑧𝐴 ∧ [𝑧 / 𝑥]𝜑)
15 nfv 1508 . . . 4 𝑧(𝑦𝐴𝜓)
16 eleq1 2220 . . . . 5 (𝑧 = 𝑦 → (𝑧𝐴𝑦𝐴))
17 sbequ 1820 . . . . . 6 (𝑧 = 𝑦 → ([𝑧 / 𝑥]𝜑 ↔ [𝑦 / 𝑥]𝜑))
18 cbvrab.4 . . . . . . 7 𝑥𝜓
19 cbvrab.5 . . . . . . 7 (𝑥 = 𝑦 → (𝜑𝜓))
2018, 19sbie 1771 . . . . . 6 ([𝑦 / 𝑥]𝜑𝜓)
2117, 20bitrdi 195 . . . . 5 (𝑧 = 𝑦 → ([𝑧 / 𝑥]𝜑𝜓))
2216, 21anbi12d 465 . . . 4 (𝑧 = 𝑦 → ((𝑧𝐴 ∧ [𝑧 / 𝑥]𝜑) ↔ (𝑦𝐴𝜓)))
2314, 15, 22cbvab 2281 . . 3 {𝑧 ∣ (𝑧𝐴 ∧ [𝑧 / 𝑥]𝜑)} = {𝑦 ∣ (𝑦𝐴𝜓)}
249, 23eqtri 2178 . 2 {𝑥 ∣ (𝑥𝐴𝜑)} = {𝑦 ∣ (𝑦𝐴𝜓)}
25 df-rab 2444 . 2 {𝑥𝐴𝜑} = {𝑥 ∣ (𝑥𝐴𝜑)}
26 df-rab 2444 . 2 {𝑦𝐴𝜓} = {𝑦 ∣ (𝑦𝐴𝜓)}
2724, 25, 263eqtr4i 2188 1 {𝑥𝐴𝜑} = {𝑦𝐴𝜓}
 Colors of variables: wff set class Syntax hints:   → wi 4   ∧ wa 103   ↔ wb 104   = wceq 1335  Ⅎwnf 1440  [wsb 1742   ∈ wcel 2128  {cab 2143  Ⅎwnfc 2286  {crab 2439 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1427  ax-7 1428  ax-gen 1429  ax-ie1 1473  ax-ie2 1474  ax-8 1484  ax-10 1485  ax-11 1486  ax-i12 1487  ax-bndl 1489  ax-4 1490  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2139 This theorem depends on definitions:  df-bi 116  df-nf 1441  df-sb 1743  df-clab 2144  df-cleq 2150  df-clel 2153  df-nfc 2288  df-rab 2444 This theorem is referenced by:  cbvrabv  2711  elrabsf  2975  tfis  4540
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