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Mirrors > Home > MPE Home > Th. List > dffr6 | Structured version Visualization version GIF version |
Description: Alternate definition of df-fr 5589. See dffr5 34330 for a definition without dummy variables (but note that their equivalence uses ax-sep 5257). (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 4566 | . . . . . . 7 ⊢ (𝑥 ∈ 𝒫 𝐴 ↔ 𝑥 ⊆ 𝐴) | |
2 | 1 | bicomi 223 | . . . . . 6 ⊢ (𝑥 ⊆ 𝐴 ↔ 𝑥 ∈ 𝒫 𝐴) |
3 | velsn 4603 | . . . . . . . 8 ⊢ (𝑥 ∈ {∅} ↔ 𝑥 = ∅) | |
4 | 3 | bicomi 223 | . . . . . . 7 ⊢ (𝑥 = ∅ ↔ 𝑥 ∈ {∅}) |
5 | 4 | necon3abii 2991 | . . . . . 6 ⊢ (𝑥 ≠ ∅ ↔ ¬ 𝑥 ∈ {∅}) |
6 | 2, 5 | anbi12i 628 | . . . . 5 ⊢ ((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) ↔ (𝑥 ∈ 𝒫 𝐴 ∧ ¬ 𝑥 ∈ {∅})) |
7 | eldif 3921 | . . . . 5 ⊢ (𝑥 ∈ (𝒫 𝐴 ∖ {∅}) ↔ (𝑥 ∈ 𝒫 𝐴 ∧ ¬ 𝑥 ∈ {∅})) | |
8 | 6, 7 | bitr4i 278 | . . . 4 ⊢ ((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) ↔ 𝑥 ∈ (𝒫 𝐴 ∖ {∅})) |
9 | 8 | imbi1i 350 | . . 3 ⊢ (((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦) ↔ (𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦)) |
10 | 9 | albii 1822 | . 2 ⊢ (∀𝑥((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦) ↔ ∀𝑥(𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦)) |
11 | df-fr 5589 | . 2 ⊢ (𝑅 Fr 𝐴 ↔ ∀𝑥((𝑥 ⊆ 𝐴 ∧ 𝑥 ≠ ∅) → ∃𝑦 ∈ 𝑥 ∀𝑧 ∈ 𝑥 ¬ 𝑧𝑅𝑦)) | |
12 | df-ral 3066 | . 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 205 ∧ wa 397 ∀wal 1540 = wceq 1542 ∈ wcel 2107 ≠ wne 2944 ∀wral 3065 ∃wrex 3074 ∖ cdif 3908 ⊆ wss 3911 ∅c0 4283 𝒫 cpw 4561 {csn 4587 class class class wbr 5106 Fr wfr 5586 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1798 ax-4 1812 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-ext 2708 |
This theorem depends on definitions: df-bi 206 df-an 398 df-tru 1545 df-ex 1783 df-sb 2069 df-clab 2715 df-cleq 2729 df-clel 2815 df-ne 2945 df-ral 3066 df-v 3448 df-dif 3914 df-in 3918 df-ss 3928 df-pw 4563 df-sn 4588 df-fr 5589 |
This theorem is referenced by: frd 5593 |
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