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Theorem indif 3157
 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 494 . . 3 ((x A (x A ¬ x B)) ↔ (x A ¬ x B))
2 elin 3103 . . . 4 (x (A ∩ (AB)) ↔ (x A x (AB)))
3 eldif 2904 . . . . 5 (x (AB) ↔ (x A ¬ x B))
43anbi2i 433 . . . 4 ((x A x (AB)) ↔ (x A (x A ¬ x B)))
52, 4bitri 173 . . 3 (x (A ∩ (AB)) ↔ (x A (x A ¬ x B)))
61, 5, 33bitr4i 201 . 2 (x (A ∩ (AB)) ↔ x (AB))
76eqriv 2019 1 (A ∩ (AB)) = (AB)
 Colors of variables: wff set class Syntax hints:  ¬ wn 3   ∧ wa 97   = wceq 1228   ∈ wcel 1374   ∖ cdif 2891   ∩ cin 2893 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 532  ax-in2 533  ax-io 617  ax-5 1316  ax-7 1317  ax-gen 1318  ax-ie1 1363  ax-ie2 1364  ax-8 1376  ax-10 1377  ax-11 1378  ax-i12 1379  ax-bnd 1380  ax-4 1381  ax-17 1400  ax-i9 1404  ax-ial 1409  ax-i5r 1410  ax-ext 2004 This theorem depends on definitions:  df-bi 110  df-tru 1231  df-nf 1330  df-sb 1628  df-clab 2009  df-cleq 2015  df-clel 2018  df-nfc 2149  df-v 2537  df-dif 2897  df-in 2901 This theorem is referenced by:  resdif  5073
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