Theorem csbie 3888

Description: Conversion of implicit substitution to explicit substitution into a class. (Contributed by AV, 2-Dec-2019.) Reduce axiom usage. (Revised by GG, 15-Oct-2024.)

Hypotheses

Ref	Expression
csbie.1	⊢ 𝐴 ∈ V
csbie.2	⊢ (𝑥 = 𝐴 → 𝐵 = 𝐶)

Assertion

Ref	Expression
csbie	⊢ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶

Distinct variable groups:   𝑥,𝐴   𝑥,𝐶

Allowed substitution hint:   𝐵(𝑥)

Proof of Theorem csbie

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-csb 3854	. 2 ⊢ ⦋𝐴 / 𝑥⦌𝐵 = {𝑦 ∣ [𝐴 / 𝑥]𝑦 ∈ 𝐵}
2		csbie.1	. . . 4 ⊢ 𝐴 ∈ V
3		csbie.2	. . . . 5 ⊢ (𝑥 = 𝐴 → 𝐵 = 𝐶)
4	3	eleq2d 2814	. . . 4 ⊢ (𝑥 = 𝐴 → (𝑦 ∈ 𝐵 ↔ 𝑦 ∈ 𝐶))
5	2, 4	sbcie 3786	. . 3 ⊢ ([𝐴 / 𝑥]𝑦 ∈ 𝐵 ↔ 𝑦 ∈ 𝐶)
6	5	abbii 2796	. 2 ⊢ {𝑦 ∣ [𝐴 / 𝑥]𝑦 ∈ 𝐵} = {𝑦 ∣ 𝑦 ∈ 𝐶}
7		abid2 2865	. 2 ⊢ {𝑦 ∣ 𝑦 ∈ 𝐶} = 𝐶
8	1, 6, 7	3eqtri 2756	1 ⊢ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶

Syntax hints:   → wi 4   = wceq 1540   ∈ wcel 2109  {cab 2707  Vcvv 3438  [wsbc 3744  ⦋csb 3853

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-ext 2701

This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1543  df-ex 1780  df-sb 2066  df-clab 2708  df-cleq 2721  df-clel 2803  df-sbc 3745  df-csb 3854

This theorem is referenced by:  pofun  5549  eqerlem  8667  mptnn0fsuppd  13923  fsum  15645  fsumcnv  15698  fsumshftm  15706  fsum0diag2  15708  fprod  15866  fprodcnv  15908  bpolyval  15974  ruclem1  16158  odfval  19429  odval  19431  psrass1lem  21857  selvval  22038  mamufval  22295  pm2mpval  22698  isibl  25682  dfitg  25686  dvfsumlem2  25949  dvfsumlem2OLD  25950  fsumdvdsmul  27121  fsumdvdsmulOLD  27123  precsexlem3  28134  disjxpin  32550  poimirlem1  37600  poimirlem5  37604  poimirlem15  37614  poimirlem16  37615  poimirlem17  37616  poimirlem19  37618  poimirlem20  37619  poimirlem22  37621  poimirlem24  37623  poimirlem28  37627  evlselv  42560  fphpd  42789  monotuz  42914  oddcomabszz  42917  fnwe2val  43022  fnwe2lem1  43023  dfswapf2  49234  dfinito4  49474