Theorem clelsb1fw 2908

Description: Substitution for the first argument of the membership predicate in an atomic formula (class version of elsb1 2113). Version of clelsb1f 2909 with a disjoint variable condition, which does not require ax-13 2370. (Contributed by Rodolfo Medina, 28-Apr-2010.) Avoid ax-13 2370. (Revised by Gino Giotto, 10-Jan-2024.)

Hypothesis

Ref	Expression
clelsb1fw.1	⊢ Ⅎ𝑥𝐴

Assertion

Ref	Expression
clelsb1fw	⊢ ([𝑦 / 𝑥]𝑥 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴)

Distinct variable group:   𝑥,𝑦

Allowed substitution hints:   𝐴(𝑥,𝑦)

Proof of Theorem clelsb1fw

Dummy variable 𝑤 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		clelsb1fw.1	. . . 4 ⊢ Ⅎ𝑥𝐴
2	1	nfcri 2891	. . 3 ⊢ Ⅎ𝑥 𝑤 ∈ 𝐴
3	2	sbco2v 2326	. 2 ⊢ ([𝑦 / 𝑥][𝑥 / 𝑤]𝑤 ∈ 𝐴 ↔ [𝑦 / 𝑤]𝑤 ∈ 𝐴)
4		clelsb1 2864	. . 3 ⊢ ([𝑥 / 𝑤]𝑤 ∈ 𝐴 ↔ 𝑥 ∈ 𝐴)
5	4	sbbii 2078	. 2 ⊢ ([𝑦 / 𝑥][𝑥 / 𝑤]𝑤 ∈ 𝐴 ↔ [𝑦 / 𝑥]𝑥 ∈ 𝐴)
6		clelsb1 2864	. 2 ⊢ ([𝑦 / 𝑤]𝑤 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴)
7	3, 5, 6	3bitr3i 300	1 ⊢ ([𝑦 / 𝑥]𝑥 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴)

Syntax hints:   ↔ wb 205  [wsb 2066   ∈ wcel 2105  Ⅎwnfc 2884

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 1912  ax-6 1970  ax-7 2010  ax-8 2107  ax-10 2136  ax-11 2153  ax-12 2170

This theorem depends on definitions:  df-bi 206  df-an 397  df-ex 1781  df-nf 1785  df-sb 2067  df-clel 2814  df-nfc 2886

This theorem is referenced by:  rmo3f  3678  suppss2f  31105  fmptdF  31124  disjdsct  31166  esumpfinvalf  32180