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Mirrors > Home > ILE Home > Th. List > vjust | GIF version |
Description: Soundness justification theorem for df-v 2603. (Contributed by Rodolfo Medina, 27-Apr-2010.) |
Ref | Expression |
---|---|
vjust | ⊢ {𝑥 ∣ 𝑥 = 𝑥} = {𝑦 ∣ 𝑦 = 𝑦} |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | equid 1629 | . . . . 5 ⊢ 𝑥 = 𝑥 | |
2 | 1 | sbt 1707 | . . . 4 ⊢ [𝑧 / 𝑥]𝑥 = 𝑥 |
3 | equid 1629 | . . . . 5 ⊢ 𝑦 = 𝑦 | |
4 | 3 | sbt 1707 | . . . 4 ⊢ [𝑧 / 𝑦]𝑦 = 𝑦 |
5 | 2, 4 | 2th 172 | . . 3 ⊢ ([𝑧 / 𝑥]𝑥 = 𝑥 ↔ [𝑧 / 𝑦]𝑦 = 𝑦) |
6 | df-clab 2068 | . . 3 ⊢ (𝑧 ∈ {𝑥 ∣ 𝑥 = 𝑥} ↔ [𝑧 / 𝑥]𝑥 = 𝑥) | |
7 | df-clab 2068 | . . 3 ⊢ (𝑧 ∈ {𝑦 ∣ 𝑦 = 𝑦} ↔ [𝑧 / 𝑦]𝑦 = 𝑦) | |
8 | 5, 6, 7 | 3bitr4i 210 | . 2 ⊢ (𝑧 ∈ {𝑥 ∣ 𝑥 = 𝑥} ↔ 𝑧 ∈ {𝑦 ∣ 𝑦 = 𝑦}) |
9 | 8 | eqriv 2078 | 1 ⊢ {𝑥 ∣ 𝑥 = 𝑥} = {𝑦 ∣ 𝑦 = 𝑦} |
Colors of variables: wff set class |
Syntax hints: = wceq 1284 ∈ wcel 1433 [wsb 1685 {cab 2067 |
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-5 1376 ax-gen 1378 ax-ie1 1422 ax-ie2 1423 ax-8 1435 ax-4 1440 ax-17 1459 ax-i9 1463 ax-ial 1467 ax-ext 2063 |
This theorem depends on definitions: df-bi 115 df-nf 1390 df-sb 1686 df-clab 2068 df-cleq 2074 |
This theorem is referenced by: (None) |
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