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Mirrors > Home > ILE Home > Th. List > clelsb4 | GIF version |
Description: Substitution applied to an atomic wff (class version of elsb4 1953). (Contributed by Jim Kingdon, 22-Nov-2018.) |
Ref | Expression |
---|---|
clelsb4 | ⊢ ([𝑦 / 𝑥]𝐴 ∈ 𝑥 ↔ 𝐴 ∈ 𝑦) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nfv 1509 | . . 3 ⊢ Ⅎ𝑥 𝐴 ∈ 𝑤 | |
2 | 1 | sbco2 1939 | . 2 ⊢ ([𝑦 / 𝑥][𝑥 / 𝑤]𝐴 ∈ 𝑤 ↔ [𝑦 / 𝑤]𝐴 ∈ 𝑤) |
3 | nfv 1509 | . . . 4 ⊢ Ⅎ𝑤 𝐴 ∈ 𝑥 | |
4 | eleq2 2204 | . . . 4 ⊢ (𝑤 = 𝑥 → (𝐴 ∈ 𝑤 ↔ 𝐴 ∈ 𝑥)) | |
5 | 3, 4 | sbie 1765 | . . 3 ⊢ ([𝑥 / 𝑤]𝐴 ∈ 𝑤 ↔ 𝐴 ∈ 𝑥) |
6 | 5 | sbbii 1739 | . 2 ⊢ ([𝑦 / 𝑥][𝑥 / 𝑤]𝐴 ∈ 𝑤 ↔ [𝑦 / 𝑥]𝐴 ∈ 𝑥) |
7 | nfv 1509 | . . 3 ⊢ Ⅎ𝑤 𝐴 ∈ 𝑦 | |
8 | eleq2 2204 | . . 3 ⊢ (𝑤 = 𝑦 → (𝐴 ∈ 𝑤 ↔ 𝐴 ∈ 𝑦)) | |
9 | 7, 8 | sbie 1765 | . 2 ⊢ ([𝑦 / 𝑤]𝐴 ∈ 𝑤 ↔ 𝐴 ∈ 𝑦) |
10 | 2, 6, 9 | 3bitr3i 209 | 1 ⊢ ([𝑦 / 𝑥]𝐴 ∈ 𝑥 ↔ 𝐴 ∈ 𝑦) |
Colors of variables: wff set class |
Syntax hints: ↔ wb 104 ∈ wcel 1481 [wsb 1736 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-io 699 ax-5 1424 ax-7 1425 ax-gen 1426 ax-ie1 1470 ax-ie2 1471 ax-8 1483 ax-10 1484 ax-11 1485 ax-i12 1486 ax-bndl 1487 ax-4 1488 ax-17 1507 ax-i9 1511 ax-ial 1515 ax-i5r 1516 ax-ext 2122 |
This theorem depends on definitions: df-bi 116 df-nf 1438 df-sb 1737 df-cleq 2133 df-clel 2136 |
This theorem is referenced by: peano1 4516 peano2 4517 |
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