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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 5420 | . . 3 ⊢ (𝐴 ⊆ 𝐵 ↔ 𝒫 𝐴 ⊆ 𝒫 𝐵) | |
| 2 | pweqb 5427 | . . . 4 ⊢ (𝐴 = 𝐵 ↔ 𝒫 𝐴 = 𝒫 𝐵) | |
| 3 | 2 | necon3bii 3012 | . . 3 ⊢ (𝐴 ≠ 𝐵 ↔ 𝒫 𝐴 ≠ 𝒫 𝐵) |
| 4 | 1, 3 | anbi12i 639 | . 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐴 ≠ 𝐵) ↔ (𝒫 𝐴 ⊆ 𝒫 𝐵 ∧ 𝒫 𝐴 ≠ 𝒫 𝐵)) |
| 5 | df-pss 3927 | . 2 ⊢ (𝐴 ⊊ 𝐵 ↔ (𝐴 ⊆ 𝐵 ∧ 𝐴 ≠ 𝐵)) | |
| 6 | df-pss 3927 | . 2 ⊢ (𝒫 𝐴 ⊊ 𝒫 𝐵 ↔ (𝒫 𝐴 ⊆ 𝒫 𝐵 ∧ 𝒫 𝐴 ≠ 𝒫 𝐵)) | |
| 7 | 4, 5, 6 | 3bitr4i 306 | 1 ⊢ (𝐴 ⊊ 𝐵 ↔ 𝒫 𝐴 ⊊ 𝒫 𝐵) |
| Colors of variables: wff setvar class |
| Syntax hints: ↔ wb 209 ∧ wa 400 ≠ wne 2960 ⊆ wss 3907 ⊊ wpss 3908 𝒫 cpw 4558 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1818 ax-4 1832 ax-5 1933 ax-6 1990 ax-7 2031 ax-8 2147 ax-9 2155 ax-ext 2737 ax-sep 5250 ax-pr 5394 |
| This theorem depends on definitions: df-bi 210 df-an 401 df-or 861 df-tru 1566 df-ex 1803 df-sb 2094 df-clab 2744 df-cleq 2757 df-clel 2840 df-ne 2961 df-v 3459 df-un 3912 df-ss 3924 df-pss 3927 df-pw 4560 df-sn 4586 df-pr 4588 |
| This theorem is referenced by: (None) |
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