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| Mirrors > Home > MPE Home > Th. List > Mathboxes > psspwb | Structured version Visualization version GIF version | ||
| Description: Classes are proper subclasses if and only if their power classes are proper subclasses. (Contributed by Steven Nguyen, 17-Jul-2022.) |
| Ref | Expression |
|---|---|
| psspwb | ⊢ (𝐴 ⊊ 𝐵 ↔ 𝒫 𝐴 ⊊ 𝒫 𝐵) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sspwb 5415 | . . 3 ⊢ (𝐴 ⊆ 𝐵 ↔ 𝒫 𝐴 ⊆ 𝒫 𝐵) | |
| 2 | pweqb 5422 | . . . 4 ⊢ (𝐴 = 𝐵 ↔ 𝒫 𝐴 = 𝒫 𝐵) | |
| 3 | 2 | necon3bii 3008 | . . 3 ⊢ (𝐴 ≠ 𝐵 ↔ 𝒫 𝐴 ≠ 𝒫 𝐵) |
| 4 | 1, 3 | anbi12i 637 | . 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐴 ≠ 𝐵) ↔ (𝒫 𝐴 ⊆ 𝒫 𝐵 ∧ 𝒫 𝐴 ≠ 𝒫 𝐵)) |
| 5 | df-pss 3924 | . 2 ⊢ (𝐴 ⊊ 𝐵 ↔ (𝐴 ⊆ 𝐵 ∧ 𝐴 ≠ 𝐵)) | |
| 6 | df-pss 3924 | . 2 ⊢ (𝒫 𝐴 ⊊ 𝒫 𝐵 ↔ (𝒫 𝐴 ⊆ 𝒫 𝐵 ∧ 𝒫 𝐴 ≠ 𝒫 𝐵)) | |
| 7 | 4, 5, 6 | 3bitr4i 305 | 1 ⊢ (𝐴 ⊊ 𝐵 ↔ 𝒫 𝐴 ⊊ 𝒫 𝐵) |
| Colors of variables: wff setvar class |
| Syntax hints: ↔ wb 208 ∧ wa 399 ≠ wne 2956 ⊆ wss 3904 ⊊ wpss 3905 𝒫 cpw 4554 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1814 ax-4 1828 ax-5 1929 ax-6 1986 ax-7 2027 ax-8 2143 ax-9 2151 ax-ext 2733 ax-sep 5245 ax-pr 5389 |
| This theorem depends on definitions: df-bi 209 df-an 400 df-or 859 df-tru 1562 df-ex 1799 df-sb 2090 df-clab 2740 df-cleq 2753 df-clel 2836 df-ne 2957 df-v 3455 df-un 3909 df-ss 3921 df-pss 3924 df-pw 4556 df-sn 4582 df-pr 4584 |
| This theorem is referenced by: (None) |
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