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Theorem indif 3402
Description: Intersection with class difference. Theorem 34 of [Suppes] p. 29. (Contributed by NM, 17-Aug-2004.)
Assertion
Ref Expression
indif (𝐴 ∩ (𝐴𝐵)) = (𝐴𝐵)

Proof of Theorem indif
Dummy variable 𝑥 is distinct from all other variables.
StepHypRef Expression
1 anabs5 573 . . 3 ((𝑥𝐴 ∧ (𝑥𝐴 ∧ ¬ 𝑥𝐵)) ↔ (𝑥𝐴 ∧ ¬ 𝑥𝐵))
2 elin 3342 . . . 4 (𝑥 ∈ (𝐴 ∩ (𝐴𝐵)) ↔ (𝑥𝐴𝑥 ∈ (𝐴𝐵)))
3 eldif 3162 . . . . 5 (𝑥 ∈ (𝐴𝐵) ↔ (𝑥𝐴 ∧ ¬ 𝑥𝐵))
43anbi2i 457 . . . 4 ((𝑥𝐴𝑥 ∈ (𝐴𝐵)) ↔ (𝑥𝐴 ∧ (𝑥𝐴 ∧ ¬ 𝑥𝐵)))
52, 4bitri 184 . . 3 (𝑥 ∈ (𝐴 ∩ (𝐴𝐵)) ↔ (𝑥𝐴 ∧ (𝑥𝐴 ∧ ¬ 𝑥𝐵)))
61, 5, 33bitr4i 212 . 2 (𝑥 ∈ (𝐴 ∩ (𝐴𝐵)) ↔ 𝑥 ∈ (𝐴𝐵))
76eqriv 2190 1 (𝐴 ∩ (𝐴𝐵)) = (𝐴𝐵)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wa 104   = wceq 1364  wcel 2164  cdif 3150  cin 3152
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-in1 615  ax-in2 616  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2175
This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-v 2762  df-dif 3155  df-in 3159
This theorem is referenced by:  resdif  5522
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