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Theorem cbvralfw 3437
Description: Rule used to change bound variables, using implicit substitution. Version of cbvralf 3439 with a disjoint variable condition, which does not require ax-13 2390. (Contributed by NM, 7-Mar-2004.) (Revised by Gino Giotto, 10-Jan-2024.)
Hypotheses
Ref Expression
cbvralfw.1 𝑥𝐴
cbvralfw.2 𝑦𝐴
cbvralfw.3 𝑦𝜑
cbvralfw.4 𝑥𝜓
cbvralfw.5 (𝑥 = 𝑦 → (𝜑𝜓))
Assertion
Ref Expression
cbvralfw (∀𝑥𝐴 𝜑 ↔ ∀𝑦𝐴 𝜓)
Distinct variable group:   𝑥,𝑦
Allowed substitution hints:   𝜑(𝑥,𝑦)   𝜓(𝑥,𝑦)   𝐴(𝑥,𝑦)

Proof of Theorem cbvralfw
Dummy variable 𝑧 is distinct from all other variables.
StepHypRef Expression
1 nfv 1915 . . . 4 𝑧(𝑥𝐴𝜑)
2 cbvralfw.1 . . . . . 6 𝑥𝐴
32nfcri 2971 . . . . 5 𝑥 𝑧𝐴
4 nfs1v 2160 . . . . 5 𝑥[𝑧 / 𝑥]𝜑
53, 4nfim 1897 . . . 4 𝑥(𝑧𝐴 → [𝑧 / 𝑥]𝜑)
6 eleq1w 2895 . . . . 5 (𝑥 = 𝑧 → (𝑥𝐴𝑧𝐴))
7 sbequ12 2253 . . . . 5 (𝑥 = 𝑧 → (𝜑 ↔ [𝑧 / 𝑥]𝜑))
86, 7imbi12d 347 . . . 4 (𝑥 = 𝑧 → ((𝑥𝐴𝜑) ↔ (𝑧𝐴 → [𝑧 / 𝑥]𝜑)))
91, 5, 8cbvalv1 2361 . . 3 (∀𝑥(𝑥𝐴𝜑) ↔ ∀𝑧(𝑧𝐴 → [𝑧 / 𝑥]𝜑))
10 cbvralfw.2 . . . . . 6 𝑦𝐴
1110nfcri 2971 . . . . 5 𝑦 𝑧𝐴
12 cbvralfw.3 . . . . . 6 𝑦𝜑
1312nfsbv 2349 . . . . 5 𝑦[𝑧 / 𝑥]𝜑
1411, 13nfim 1897 . . . 4 𝑦(𝑧𝐴 → [𝑧 / 𝑥]𝜑)
15 nfv 1915 . . . 4 𝑧(𝑦𝐴𝜓)
16 eleq1w 2895 . . . . 5 (𝑧 = 𝑦 → (𝑧𝐴𝑦𝐴))
17 sbequ 2090 . . . . . 6 (𝑧 = 𝑦 → ([𝑧 / 𝑥]𝜑 ↔ [𝑦 / 𝑥]𝜑))
18 cbvralfw.4 . . . . . . 7 𝑥𝜓
19 cbvralfw.5 . . . . . . 7 (𝑥 = 𝑦 → (𝜑𝜓))
2018, 19sbiev 2330 . . . . . 6 ([𝑦 / 𝑥]𝜑𝜓)
2117, 20syl6bb 289 . . . . 5 (𝑧 = 𝑦 → ([𝑧 / 𝑥]𝜑𝜓))
2216, 21imbi12d 347 . . . 4 (𝑧 = 𝑦 → ((𝑧𝐴 → [𝑧 / 𝑥]𝜑) ↔ (𝑦𝐴𝜓)))
2314, 15, 22cbvalv1 2361 . . 3 (∀𝑧(𝑧𝐴 → [𝑧 / 𝑥]𝜑) ↔ ∀𝑦(𝑦𝐴𝜓))
249, 23bitri 277 . 2 (∀𝑥(𝑥𝐴𝜑) ↔ ∀𝑦(𝑦𝐴𝜓))
25 df-ral 3143 . 2 (∀𝑥𝐴 𝜑 ↔ ∀𝑥(𝑥𝐴𝜑))
26 df-ral 3143 . 2 (∀𝑦𝐴 𝜓 ↔ ∀𝑦(𝑦𝐴𝜓))
2724, 25, 263bitr4i 305 1 (∀𝑥𝐴 𝜑 ↔ ∀𝑦𝐴 𝜓)
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 208  wal 1535  wnf 1784  [wsb 2069  wcel 2114  wnfc 2961  wral 3138
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2116  ax-10 2145  ax-11 2161  ax-12 2177
This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-ex 1781  df-nf 1785  df-sb 2070  df-clel 2893  df-nfc 2963  df-ral 3143
This theorem is referenced by:  cbvrexfw  3438  cbvralw  3441  reusv2lem4  5302  reusv2  5304  ffnfvf  6883  nnwof  12315  nnindf  30535  scottexf  35461  scott0f  35462  evth2f  41321  evthf  41333  supxrleubrnmptf  41776  stoweidlem14  42348  stoweidlem28  42362  stoweidlem59  42393
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