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| Mirrors > Home > MPE Home > Th. List > dffr6 | Structured version Visualization version GIF version | ||
| Description: Alternate definition of df-fr 5637. See dffr5 35754 for a definition without dummy variables (but note that their equivalence uses ax-sep 5296). (Contributed by BJ, 16-Nov-2024.) |
| Ref | Expression |
|---|---|
| dffr6 | ⊢ (𝑅 Fr 𝐴 ↔ ∀𝑥 ∈ (𝒫 𝐴 ∖ {∅})∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | velpw 4605 | . . . . . . 7 ⊢ (𝑥 ∈ 𝒫 𝐴 ↔ 𝑥 ⊆ 𝐴) | |
| 2 | 1 | bicomi 224 | . . . . . 6 ⊢ (𝑥 ⊆ 𝐴 ↔ 𝑥 ∈ 𝒫 𝐴) |
| 3 | velsn 4642 | . . . . . . . 8 ⊢ (𝑥 ∈ {∅} ↔ 𝑥 = ∅) | |
| 4 | 3 | bicomi 224 | . . . . . . 7 ⊢ (𝑥 = ∅ ↔ 𝑥 ∈ {∅}) |
| 5 | 4 | necon3abii 2987 | . . . . . 6 ⊢ (𝑥 ≠ ∅ ↔ ¬ 𝑥 ∈ {∅}) |
| 6 | 2, 5 | anbi12i 628 | . . . . 5 ⊢ ((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) ↔ (𝑥 ∈ 𝒫 𝐴 ∧ ¬ 𝑥 ∈ {∅})) |
| 7 | eldif 3961 | . . . . 5 ⊢ (𝑥 ∈ (𝒫 𝐴 ∖ {∅}) ↔ (𝑥 ∈ 𝒫 𝐴 ∧ ¬ 𝑥 ∈ {∅})) | |
| 8 | 6, 7 | bitr4i 278 | . . . 4 ⊢ ((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) ↔ 𝑥 ∈ (𝒫 𝐴 ∖ {∅})) |
| 9 | 8 | imbi1i 349 | . . 3 ⊢ (((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦) ↔ (𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦)) |
| 10 | 9 | albii 1819 | . 2 ⊢ (∀𝑥((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦) ↔ ∀𝑥(𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦)) |
| 11 | df-fr 5637 | . 2 ⊢ (𝑅 Fr 𝐴 ↔ ∀𝑥((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦)) | |
| 12 | df-ral 3062 | . 2 ⊢ (∀𝑥 ∈ (𝒫 𝐴 ∖ {∅})∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦 ↔ ∀𝑥(𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦)) | |
| 13 | 10, 11, 12 | 3bitr4i 303 | 1 ⊢ (𝑅 Fr 𝐴 ↔ ∀𝑥 ∈ (𝒫 𝐴 ∖ {∅})∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦) |
| Colors of variables: wff setvar class |
| Syntax hints: ¬ wn 3 → wi 4 ↔ wb 206 ∧ wa 395 ∀wal 1538 = wceq 1540 ∈ wcel 2108 ≠ wne 2940 ∀wral 3061 ∃wrex 3070 ∖ cdif 3948 ⊆ wss 3951 ∅c0 4333 𝒫 cpw 4600 {csn 4626 class class class wbr 5143 Fr wfr 5634 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1795 ax-4 1809 ax-5 1910 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-ext 2708 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-tru 1543 df-ex 1780 df-sb 2065 df-clab 2715 df-cleq 2729 df-clel 2816 df-ne 2941 df-ral 3062 df-v 3482 df-dif 3954 df-ss 3968 df-pw 4602 df-sn 4627 df-fr 5637 |
| This theorem is referenced by: frd 5641 |
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