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Theorem nfreuw 3300
Description: Bound-variable hypothesis builder for restricted unique existence. Version of nfreu 3302 with a disjoint variable condition, which does not require ax-13 2372. (Contributed by NM, 30-Oct-2010.) (Revised by Gino Giotto, 10-Jan-2024.)
Hypotheses
Ref Expression
nfreuw.1 𝑥𝐴
nfreuw.2 𝑥𝜑
Assertion
Ref Expression
nfreuw 𝑥∃!𝑦𝐴 𝜑
Distinct variable group:   𝑥,𝑦
Allowed substitution hints:   𝜑(𝑥,𝑦)   𝐴(𝑥,𝑦)

Proof of Theorem nfreuw
StepHypRef Expression
1 df-reu 3070 . . 3 (∃!𝑦𝐴 𝜑 ↔ ∃!𝑦(𝑦𝐴𝜑))
2 nftru 1808 . . . 4 𝑦
3 nfcvd 2907 . . . . . 6 (⊤ → 𝑥𝑦)
4 nfreuw.1 . . . . . . 7 𝑥𝐴
54a1i 11 . . . . . 6 (⊤ → 𝑥𝐴)
63, 5nfeld 2917 . . . . 5 (⊤ → Ⅎ𝑥 𝑦𝐴)
7 nfreuw.2 . . . . . 6 𝑥𝜑
87a1i 11 . . . . 5 (⊤ → Ⅎ𝑥𝜑)
96, 8nfand 1901 . . . 4 (⊤ → Ⅎ𝑥(𝑦𝐴𝜑))
102, 9nfeudw 2591 . . 3 (⊤ → Ⅎ𝑥∃!𝑦(𝑦𝐴𝜑))
111, 10nfxfrd 1857 . 2 (⊤ → Ⅎ𝑥∃!𝑦𝐴 𝜑)
1211mptru 1546 1 𝑥∃!𝑦𝐴 𝜑
Colors of variables: wff setvar class
Syntax hints:  wa 395  wtru 1540  wnf 1787  wcel 2108  ∃!weu 2568  wnfc 2886  ∃!wreu 3065
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1799  ax-4 1813  ax-5 1914  ax-6 1972  ax-7 2012  ax-8 2110  ax-9 2118  ax-10 2139  ax-11 2156  ax-12 2173  ax-ext 2709
This theorem depends on definitions:  df-bi 206  df-an 396  df-or 844  df-tru 1542  df-ex 1784  df-nf 1788  df-mo 2540  df-eu 2569  df-cleq 2730  df-clel 2817  df-nfc 2888  df-reu 3070
This theorem is referenced by:  sbcreu  3805  reuccatpfxs1  14388  2reu7  44490  2reu8  44491
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