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Theorem dffr6 5644
Description: Alternate definition of df-fr 5641. See dffr5 35734 for a definition without dummy variables (but note that their equivalence uses ax-sep 5302). (Contributed by BJ, 16-Nov-2024.)
Assertion
Ref Expression
dffr6 (𝑅 Fr 𝐴 ↔ ∀𝑥 ∈ (𝒫 𝐴 ∖ {∅})∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦)
Distinct variable groups:   𝑥,𝐴,𝑦,𝑧   𝑥,𝑅,𝑦,𝑧

Proof of Theorem dffr6
StepHypRef Expression
1 velpw 4610 . . . . . . 7 (𝑥 ∈ 𝒫 𝐴𝑥𝐴)
21bicomi 224 . . . . . 6 (𝑥𝐴𝑥 ∈ 𝒫 𝐴)
3 velsn 4647 . . . . . . . 8 (𝑥 ∈ {∅} ↔ 𝑥 = ∅)
43bicomi 224 . . . . . . 7 (𝑥 = ∅ ↔ 𝑥 ∈ {∅})
54necon3abii 2985 . . . . . 6 (𝑥 ≠ ∅ ↔ ¬ 𝑥 ∈ {∅})
62, 5anbi12i 628 . . . . 5 ((𝑥𝐴𝑥 ≠ ∅) ↔ (𝑥 ∈ 𝒫 𝐴 ∧ ¬ 𝑥 ∈ {∅}))
7 eldif 3973 . . . . 5 (𝑥 ∈ (𝒫 𝐴 ∖ {∅}) ↔ (𝑥 ∈ 𝒫 𝐴 ∧ ¬ 𝑥 ∈ {∅}))
86, 7bitr4i 278 . . . 4 ((𝑥𝐴𝑥 ≠ ∅) ↔ 𝑥 ∈ (𝒫 𝐴 ∖ {∅}))
98imbi1i 349 . . 3 (((𝑥𝐴𝑥 ≠ ∅) → ∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦) ↔ (𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦))
109albii 1816 . 2 (∀𝑥((𝑥𝐴𝑥 ≠ ∅) → ∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦) ↔ ∀𝑥(𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦))
11 df-fr 5641 . 2 (𝑅 Fr 𝐴 ↔ ∀𝑥((𝑥𝐴𝑥 ≠ ∅) → ∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦))
12 df-ral 3060 . 2 (∀𝑥 ∈ (𝒫 𝐴 ∖ {∅})∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦 ↔ ∀𝑥(𝑥 ∈ (𝒫 𝐴 ∖ {∅}) → ∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦))
1310, 11, 123bitr4i 303 1 (𝑅 Fr 𝐴 ↔ ∀𝑥 ∈ (𝒫 𝐴 ∖ {∅})∃𝑦𝑥𝑧𝑥 ¬ 𝑧𝑅𝑦)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wb 206  wa 395  wal 1535   = wceq 1537  wcel 2106  wne 2938  wral 3059  wrex 3068  cdif 3960  wss 3963  c0 4339  𝒫 cpw 4605  {csn 4631   class class class wbr 5148   Fr wfr 5638
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1792  ax-4 1806  ax-5 1908  ax-6 1965  ax-7 2005  ax-8 2108  ax-9 2116  ax-ext 2706
This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1540  df-ex 1777  df-sb 2063  df-clab 2713  df-cleq 2727  df-clel 2814  df-ne 2939  df-ral 3060  df-v 3480  df-dif 3966  df-ss 3980  df-pw 4607  df-sn 4632  df-fr 5641
This theorem is referenced by:  frd  5645
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