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Mirrors > Home > MPE Home > Th. List > elab2gw | Structured version Visualization version GIF version |
Description: Membership in a class abstraction, using two substitution hypotheses to avoid a disjoint variable condition on 𝑥 and 𝐴, which is not usually significant since 𝐵 is usually a constant. (Contributed by SN, 16-May-2024.) |
Ref | Expression |
---|---|
elabgw.1 | ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) |
elabgw.2 | ⊢ (𝑦 = 𝐴 → (𝜓 ↔ 𝜒)) |
elab2gw.3 | ⊢ 𝐵 = {𝑥 ∣ 𝜑} |
Ref | Expression |
---|---|
elab2gw | ⊢ (𝐴 ∈ 𝑉 → (𝐴 ∈ 𝐵 ↔ 𝜒)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elab2gw.3 | . . 3 ⊢ 𝐵 = {𝑥 ∣ 𝜑} | |
2 | 1 | eleq2i 2830 | . 2 ⊢ (𝐴 ∈ 𝐵 ↔ 𝐴 ∈ {𝑥 ∣ 𝜑}) |
3 | elabgw.1 | . . 3 ⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) | |
4 | elabgw.2 | . . 3 ⊢ (𝑦 = 𝐴 → (𝜓 ↔ 𝜒)) | |
5 | 3, 4 | elabgw 3678 | . 2 ⊢ (𝐴 ∈ 𝑉 → (𝐴 ∈ {𝑥 ∣ 𝜑} ↔ 𝜒)) |
6 | 2, 5 | bitrid 283 | 1 ⊢ (𝐴 ∈ 𝑉 → (𝐴 ∈ 𝐵 ↔ 𝜒)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 206 = wceq 1536 ∈ wcel 2105 {cab 2711 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1791 ax-4 1805 ax-5 1907 ax-6 1964 ax-7 2004 ax-8 2107 ax-9 2115 ax-ext 2705 |
This theorem depends on definitions: df-bi 207 df-an 396 df-tru 1539 df-ex 1776 df-sb 2062 df-clab 2712 df-cleq 2726 df-clel 2813 |
This theorem is referenced by: elrab2w 3698 |
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