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Theorem cbvmptg 5212
Description: Rule to change the bound variable in a maps-to function, using implicit substitution. This version has bound-variable hypotheses in place of distinct variable conditions. Usage of this theorem is discouraged because it depends on ax-13 2404. See cbvmpt 5211 for a version with more disjoint variable conditions, but not requiring ax-13 2404. (Contributed by NM, 11-Sep-2011.) (New usage is discouraged.)
Hypotheses
Ref Expression
cbvmptg.1 Ⅎ𝑦𝐵
cbvmptg.2 Ⅎ𝑥𝐶
cbvmptg.3 (𝑥 = 𝑦 → 𝐵 = 𝐶)
Assertion
Ref Expression
cbvmptg (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑦 ∈ 𝐴 ↦ 𝐶)
Distinct variable groups:   𝑥,𝐴   𝑦,𝐴
Allowed substitution hints:   𝐵(𝑥, 𝑦)   𝐶(𝑥, 𝑦)

Proof of Theorem cbvmptg
StepHypRef Expression
1 nfcv 2926 . 2 Ⅎ𝑥𝐴
2 nfcv 2926 . 2 Ⅎ𝑦𝐴
3 cbvmptg.1 . 2 Ⅎ𝑦𝐵
4 cbvmptg.2 . 2 Ⅎ𝑥𝐶
5 cbvmptg.3 . 2 (𝑥 = 𝑦 → 𝐵 = 𝐶)
61, 2, 3, 4, 5cbvmptfg 5210 1 (𝑥 ∈ 𝐴 ↦ 𝐵) = (𝑦 ∈ 𝐴 ↦ 𝐶)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:   → wi 4   = wceq 1570  Ⅎwnfc 2911   ↦ cmpt 5190
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1945  ax-6 2002  ax-7 2043  ax-8 2149  ax-9 2157  ax-10 2180  ax-11 2197  ax-12 2216  ax-13 2404  ax-ext 2735
This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-3an 1105  df-tru 1573  df-fal 1583  df-ex 1813  df-nf 1817  df-sb 2102  df-clab 2742  df-cleq 2755  df-clel 2839  df-nfc 2913  df-rab 3417  df-v 3456  df-ss 3901  df-dif 4050  df-un 4154  df-nul 4282  df-if 4486  df-sn 4589  df-pr 4591  df-op 4839  df-opab 5172  df-mpt 5191
This theorem is used by:  cbvmptvg  5214
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