Theorem csbie 3881

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 3847	. 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 2846	. . . 4 ⊢ (𝑥 = 𝐴 → (𝑦 ∈ 𝐵 ↔ 𝑦 ∈ 𝐶))
5	2, 4	sbcie 3779	. . 3 ⊢ ([𝐴 / 𝑥]𝑦 ∈ 𝐵 ↔ 𝑦 ∈ 𝐶)
6	5	abbii 2827	. 2 ⊢ {𝑦 ∣ [𝐴 / 𝑥]𝑦 ∈ 𝐵} = {𝑦 ∣ 𝑦 ∈ 𝐶}
7		abid2 2897	. 2 ⊢ {𝑦 ∣ 𝑦 ∈ 𝐶} = 𝐶
8	1, 6, 7	3eqtri 2787	1 ⊢ ⦋𝐴 / 𝑥⦌𝐵 = 𝐶

This proof depends on syntax axioms:   → wi 4   = wceq 1570   ∈ wcel 2145  {cab 2738  Vcvv 3450  [wsbc 3738  ⦋csb 3846

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 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-ext 2732

This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-ex 1813  df-sb 2100  df-clab 2739  df-cleq 2752  df-clel 2835  df-sbc 3739  df-csb 3847

This theorem is used by:  pofun  5573  eqerlem  8731  mptnn0fsuppd  14110  fsum  15854  fsumcnv  15907  fsumshftm  15915  fsum0diag2  15917  fprod  16076  fprodcnv  16118  bpolyval  16183  ruclem1  16367  odfval  19708  odval  19710  psrass1lem  22203  selvval  22391  mamufval  22669  pm2mpval  23075  isibl  26048  dfitg  26052  dvfsumlem2  26309  fsumdvdsmul  27486  precsexlem3  28529  disjxpin  33116  gsummulsubdishift2s  33566  nmulprop  36861  poimirlem1  38459  poimirlem5  38463  poimirlem15  38473  poimirlem16  38474  poimirlem17  38475  poimirlem19  38477  poimirlem20  38478  poimirlem22  38480  poimirlem24  38482  poimirlem28  38486  evlselv  43539  fphpd  43761  monotuz  43886  oddcomabszz  43889  fnwe2val  43994  fnwe2lem1  43995  dfswapf2  50291  dfinito4  50531