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Mirrors > Home > ILE Home > Th. List > clelsb3 | GIF version |
Description: Substitution applied to an atomic wff (class version of elsb3 1893). (Contributed by Rodolfo Medina, 28-Apr-2010.) (Proof shortened by Andrew Salmon, 14-Jun-2011.) |
Ref | Expression |
---|---|
clelsb3 | ⊢ ([𝑥 / 𝑦]𝑦 ∈ 𝐴 ↔ 𝑥 ∈ 𝐴) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfv 1461 | . . 3 ⊢ Ⅎ𝑦 𝑤 ∈ 𝐴 | |
2 | 1 | sbco2 1880 | . 2 ⊢ ([𝑥 / 𝑦][𝑦 / 𝑤]𝑤 ∈ 𝐴 ↔ [𝑥 / 𝑤]𝑤 ∈ 𝐴) |
3 | nfv 1461 | . . . 4 ⊢ Ⅎ𝑤 𝑦 ∈ 𝐴 | |
4 | eleq1 2141 | . . . 4 ⊢ (𝑤 = 𝑦 → (𝑤 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴)) | |
5 | 3, 4 | sbie 1714 | . . 3 ⊢ ([𝑦 / 𝑤]𝑤 ∈ 𝐴 ↔ 𝑦 ∈ 𝐴) |
6 | 5 | sbbii 1688 | . 2 ⊢ ([𝑥 / 𝑦][𝑦 / 𝑤]𝑤 ∈ 𝐴 ↔ [𝑥 / 𝑦]𝑦 ∈ 𝐴) |
7 | nfv 1461 | . . 3 ⊢ Ⅎ𝑤 𝑥 ∈ 𝐴 | |
8 | eleq1 2141 | . . 3 ⊢ (𝑤 = 𝑥 → (𝑤 ∈ 𝐴 ↔ 𝑥 ∈ 𝐴)) | |
9 | 7, 8 | sbie 1714 | . 2 ⊢ ([𝑥 / 𝑤]𝑤 ∈ 𝐴 ↔ 𝑥 ∈ 𝐴) |
10 | 2, 6, 9 | 3bitr3i 208 | 1 ⊢ ([𝑥 / 𝑦]𝑦 ∈ 𝐴 ↔ 𝑥 ∈ 𝐴) |
Colors of variables: wff set class |
Syntax hints: ↔ wb 103 ∈ wcel 1433 [wsb 1685 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-io 662 ax-5 1376 ax-7 1377 ax-gen 1378 ax-ie1 1422 ax-ie2 1423 ax-8 1435 ax-10 1436 ax-11 1437 ax-i12 1438 ax-bndl 1439 ax-4 1440 ax-17 1459 ax-i9 1463 ax-ial 1467 ax-i5r 1468 ax-ext 2063 |
This theorem depends on definitions: df-bi 115 df-nf 1390 df-sb 1686 df-cleq 2074 df-clel 2077 |
This theorem is referenced by: hblem 2186 nfraldya 2400 nfrexdya 2401 cbvreu 2575 sbcel1v 2876 rmo3 2905 setindel 4281 elirr 4284 en2lp 4297 zfregfr 4316 tfi 4323 bdcriota 10674 |
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