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Theorem indifdir 3389
Description: Distribute intersection over difference. (Contributed by Scott Fenton, 14-Apr-2011.)
Assertion
Ref Expression
indifdir ((𝐴𝐵) ∩ 𝐶) = ((𝐴𝐶) ∖ (𝐵𝐶))

Proof of Theorem indifdir
Dummy variable 𝑥 is distinct from all other variables.
StepHypRef Expression
1 elin 3316 . . . 4 (𝑥 ∈ (𝐴𝐶) ↔ (𝑥𝐴𝑥𝐶))
2 elin 3316 . . . . 5 (𝑥 ∈ (𝐵𝐶) ↔ (𝑥𝐵𝑥𝐶))
32notbii 668 . . . 4 𝑥 ∈ (𝐵𝐶) ↔ ¬ (𝑥𝐵𝑥𝐶))
41, 3anbi12i 460 . . 3 ((𝑥 ∈ (𝐴𝐶) ∧ ¬ 𝑥 ∈ (𝐵𝐶)) ↔ ((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)))
5 eldif 3136 . . 3 (𝑥 ∈ ((𝐴𝐶) ∖ (𝐵𝐶)) ↔ (𝑥 ∈ (𝐴𝐶) ∧ ¬ 𝑥 ∈ (𝐵𝐶)))
6 elin 3316 . . . . 5 (𝑥 ∈ ((𝐴𝐵) ∩ 𝐶) ↔ (𝑥 ∈ (𝐴𝐵) ∧ 𝑥𝐶))
7 eldif 3136 . . . . . 6 (𝑥 ∈ (𝐴𝐵) ↔ (𝑥𝐴 ∧ ¬ 𝑥𝐵))
87anbi1i 458 . . . . 5 ((𝑥 ∈ (𝐴𝐵) ∧ 𝑥𝐶) ↔ ((𝑥𝐴 ∧ ¬ 𝑥𝐵) ∧ 𝑥𝐶))
96, 8bitri 184 . . . 4 (𝑥 ∈ ((𝐴𝐵) ∩ 𝐶) ↔ ((𝑥𝐴 ∧ ¬ 𝑥𝐵) ∧ 𝑥𝐶))
10 an32 562 . . . . 5 (((𝑥𝐴 ∧ ¬ 𝑥𝐵) ∧ 𝑥𝐶) ↔ ((𝑥𝐴𝑥𝐶) ∧ ¬ 𝑥𝐵))
11 simpl 109 . . . . . . . 8 ((𝑥𝐵𝑥𝐶) → 𝑥𝐵)
1211con3i 632 . . . . . . 7 𝑥𝐵 → ¬ (𝑥𝐵𝑥𝐶))
1312anim2i 342 . . . . . 6 (((𝑥𝐴𝑥𝐶) ∧ ¬ 𝑥𝐵) → ((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)))
14 simpl 109 . . . . . . 7 (((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)) → (𝑥𝐴𝑥𝐶))
15 ax-in2 615 . . . . . . . . . . 11 (¬ (𝑥𝐵𝑥𝐶) → ((𝑥𝐵𝑥𝐶) → ⊥))
1615expcomd 1439 . . . . . . . . . 10 (¬ (𝑥𝐵𝑥𝐶) → (𝑥𝐶 → (𝑥𝐵 → ⊥)))
1716impcom 125 . . . . . . . . 9 ((𝑥𝐶 ∧ ¬ (𝑥𝐵𝑥𝐶)) → (𝑥𝐵 → ⊥))
18 dfnot 1371 . . . . . . . . 9 𝑥𝐵 ↔ (𝑥𝐵 → ⊥))
1917, 18sylibr 134 . . . . . . . 8 ((𝑥𝐶 ∧ ¬ (𝑥𝐵𝑥𝐶)) → ¬ 𝑥𝐵)
2019adantll 476 . . . . . . 7 (((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)) → ¬ 𝑥𝐵)
2114, 20jca 306 . . . . . 6 (((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)) → ((𝑥𝐴𝑥𝐶) ∧ ¬ 𝑥𝐵))
2213, 21impbii 126 . . . . 5 (((𝑥𝐴𝑥𝐶) ∧ ¬ 𝑥𝐵) ↔ ((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)))
2310, 22bitri 184 . . . 4 (((𝑥𝐴 ∧ ¬ 𝑥𝐵) ∧ 𝑥𝐶) ↔ ((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)))
249, 23bitri 184 . . 3 (𝑥 ∈ ((𝐴𝐵) ∩ 𝐶) ↔ ((𝑥𝐴𝑥𝐶) ∧ ¬ (𝑥𝐵𝑥𝐶)))
254, 5, 243bitr4ri 213 . 2 (𝑥 ∈ ((𝐴𝐵) ∩ 𝐶) ↔ 𝑥 ∈ ((𝐴𝐶) ∖ (𝐵𝐶)))
2625eqriv 2172 1 ((𝐴𝐵) ∩ 𝐶) = ((𝐴𝐶) ∖ (𝐵𝐶))
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104   = wceq 1353  wfal 1358  wcel 2146  cdif 3124  cin 3126
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 614  ax-in2 615  ax-io 709  ax-5 1445  ax-7 1446  ax-gen 1447  ax-ie1 1491  ax-ie2 1492  ax-8 1502  ax-10 1503  ax-11 1504  ax-i12 1505  ax-bndl 1507  ax-4 1508  ax-17 1524  ax-i9 1528  ax-ial 1532  ax-i5r 1533  ax-ext 2157
This theorem depends on definitions:  df-bi 117  df-tru 1356  df-fal 1359  df-nf 1459  df-sb 1761  df-clab 2162  df-cleq 2168  df-clel 2171  df-nfc 2306  df-v 2737  df-dif 3129  df-in 3133
This theorem is referenced by: (None)
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