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Theorem inteq 3902
Description: Equality law for intersection. (Contributed by NM, 13-Sep-1999.)
Assertion
Ref Expression
inteq (𝐴 = 𝐵 𝐴 = 𝐵)

Proof of Theorem inteq
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 raleq 2705 . . 3 (𝐴 = 𝐵 → (∀𝑦𝐴 𝑥𝑦 ↔ ∀𝑦𝐵 𝑥𝑦))
21abbidv 2325 . 2 (𝐴 = 𝐵 → {𝑥 ∣ ∀𝑦𝐴 𝑥𝑦} = {𝑥 ∣ ∀𝑦𝐵 𝑥𝑦})
3 dfint2 3901 . 2 𝐴 = {𝑥 ∣ ∀𝑦𝐴 𝑥𝑦}
4 dfint2 3901 . 2 𝐵 = {𝑥 ∣ ∀𝑦𝐵 𝑥𝑦}
52, 3, 43eqtr4g 2265 1 (𝐴 = 𝐵 𝐴 = 𝐵)
Colors of variables: wff set class
Syntax hints:  wi 4   = wceq 1373  {cab 2193  wral 2486   cint 3899
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 711  ax-5 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2189
This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2194  df-cleq 2200  df-clel 2203  df-nfc 2339  df-ral 2491  df-int 3900
This theorem is referenced by:  inteqi  3903  inteqd  3904  uniintsnr  3935  rint0  3938  intexr  4210  onintexmid  4639  elreldm  4923  elxp5  5190  1stval2  6264  fundmen  6922  xpsnen  6941  fiintim  7054  elfir  7101  fiinopn  14591  bj-intexr  16043
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