ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  eqabcbw GIF version

Theorem eqabcbw 2376
Description: Version of eqabcb 2377 using implicit substitution, which requires fewer axioms. (Contributed by TM, 24-Jan-2026.)
Hypothesis
Ref Expression
eqabbw.1 (𝑥 = 𝑦 → (𝜑𝜓))
Assertion
Ref Expression
eqabcbw ({𝑥𝜑} = 𝐴 ↔ ∀𝑦(𝜓𝑦𝐴))
Distinct variable groups:   𝑥,𝑦   𝑦,𝐴   𝜑,𝑦   𝜓,𝑥
Allowed substitution hints:   𝜑(𝑥)   𝜓(𝑦)   𝐴(𝑥)

Proof of Theorem eqabcbw
StepHypRef Expression
1 eqabbw.1 . . 3 (𝑥 = 𝑦 → (𝜑𝜓))
21eqabbw 2375 . 2 (𝐴 = {𝑥𝜑} ↔ ∀𝑦(𝑦𝐴𝜓))
3 eqcom 2240 . 2 ({𝑥𝜑} = 𝐴𝐴 = {𝑥𝜑})
4 bicom 140 . . 3 ((𝜓𝑦𝐴) ↔ (𝑦𝐴𝜓))
54albii 1523 . 2 (∀𝑦(𝜓𝑦𝐴) ↔ ∀𝑦(𝑦𝐴𝜓))
62, 3, 53bitr4i 212 1 ({𝑥𝜑} = 𝐴 ↔ ∀𝑦(𝜓𝑦𝐴))
Colors of variables: wff set class
Syntax hints:  wi 4  wb 105  wal 1400   = wceq 1402  wcel 2209  {cab 2224
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220
This theorem depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234
This theorem is referenced by:  ab0w  3550
  Copyright terms: Public domain W3C validator