Theorem csbid 3864

Description: Analogue of sbid 2294 for proper substitution into a class. (Contributed by NM, 10-Nov-2005.)

Assertion

Ref	Expression
csbid	⊢ ⦋𝑥 / 𝑥⦌𝐴 = 𝐴

Proof of Theorem csbid

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		df-csb 3852	. 2 ⊢ ⦋𝑥 / 𝑥⦌𝐴 = {𝑦 ∣ [𝑥 / 𝑥]𝑦 ∈ 𝐴}
2		sbcid 3759	. . 3 ⊢ ([𝑥 / 𝑥]𝑦 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴)
3	2	abbii 2830	. 2 ⊢ {𝑦 ∣ [𝑥 / 𝑥]𝑦 ∈ 𝐴} = {𝑦 ∣ 𝑦 ∈ 𝐴}
4		abid2 2901	. 2 ⊢ {𝑦 ∣ 𝑦 ∈ 𝐴} = 𝐴
5	1, 3, 4	3eqtri 2790	1 ⊢ ⦋𝑥 / 𝑥⦌𝐴 = 𝐴

This proof depends on syntax axioms:   = wceq 1570   ∈ wcel 2147  {cab 2741  [wsbc 3742  ⦋csb 3851

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-12 2216  ax-ext 2735

This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-ex 1813  df-sb 2102  df-clab 2742  df-cleq 2755  df-clel 2839  df-sbc 3743  df-csb 3852

This theorem is used by:  csbeq1a  3865  fvmpt2f  7017  fvmpt2i  7027  fvmpocurryd  8316  fsumsplitf  15937  gsummoncoe1  22656  gsumply1eq  22657  disji2f  33243  disjif2  33247  disjabrex  33248  disjabrexf  33249  gsummpt2co  33679  measiuns  34920  fphpd  44016  disjrnmpt2  46408  climinf2mpt  46929  climinfmpt  46930  dvmptmulf  47152  sge0f1o  47597