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Theorem abeq2w 2808
Description: Version of abeq2 2862 using implicit substitution, which requires fewer axioms. (Contributed by GG and AV, 18-Sep-2024.)
Hypothesis
Ref Expression
abeq2w.1 (𝑥 = 𝑦 → (𝜑𝜓))
Assertion
Ref Expression
abeq2w (𝐴 = {𝑥𝜑} ↔ ∀𝑦(𝑦𝐴𝜓))
Distinct variable groups:   𝑥,𝑦   𝑦,𝐴   𝜑,𝑦   𝜓,𝑥
Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑦)   𝐴(𝑥)

Proof of Theorem abeq2w
StepHypRef Expression
1 dfcleq 2729 . 2 (𝐴 = {𝑥𝜑} ↔ ∀𝑦(𝑦𝐴𝑦 ∈ {𝑥𝜑}))
2 df-clab 2715 . . . . 5 (𝑦 ∈ {𝑥𝜑} ↔ [𝑦 / 𝑥]𝜑)
3 abeq2w.1 . . . . . 6 (𝑥 = 𝑦 → (𝜑𝜓))
43sbievw 2101 . . . . 5 ([𝑦 / 𝑥]𝜑𝜓)
52, 4bitri 278 . . . 4 (𝑦 ∈ {𝑥𝜑} ↔ 𝜓)
65bibi2i 341 . . 3 ((𝑦𝐴𝑦 ∈ {𝑥𝜑}) ↔ (𝑦𝐴𝜓))
76albii 1827 . 2 (∀𝑦(𝑦𝐴𝑦 ∈ {𝑥𝜑}) ↔ ∀𝑦(𝑦𝐴𝜓))
81, 7bitri 278 1 (𝐴 = {𝑥𝜑} ↔ ∀𝑦(𝑦𝐴𝜓))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 209  wal 1541   = wceq 1543  [wsb 2072  wcel 2112  {cab 2714
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1803  ax-4 1817  ax-5 1918  ax-6 1976  ax-7 2018  ax-9 2122  ax-ext 2708
This theorem depends on definitions:  df-bi 210  df-an 400  df-ex 1788  df-sb 2073  df-clab 2715  df-cleq 2728
This theorem is referenced by:  vpwex  5255  fineqvpow  32732
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