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Theorem xpundi 4563
Description: Distributive law for cross product over union. Theorem 103 of [Suppes] p. 52. (Contributed by NM, 12-Aug-2004.)
Assertion
Ref Expression
xpundi (𝐴 × (𝐵𝐶)) = ((𝐴 × 𝐵) ∪ (𝐴 × 𝐶))

Proof of Theorem xpundi
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 df-xp 4513 . 2 (𝐴 × (𝐵𝐶)) = {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦 ∈ (𝐵𝐶))}
2 df-xp 4513 . . . 4 (𝐴 × 𝐵) = {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐵)}
3 df-xp 4513 . . . 4 (𝐴 × 𝐶) = {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)}
42, 3uneq12i 3196 . . 3 ((𝐴 × 𝐵) ∪ (𝐴 × 𝐶)) = ({⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐵)} ∪ {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)})
5 elun 3185 . . . . . . 7 (𝑦 ∈ (𝐵𝐶) ↔ (𝑦𝐵𝑦𝐶))
65anbi2i 450 . . . . . 6 ((𝑥𝐴𝑦 ∈ (𝐵𝐶)) ↔ (𝑥𝐴 ∧ (𝑦𝐵𝑦𝐶)))
7 andi 790 . . . . . 6 ((𝑥𝐴 ∧ (𝑦𝐵𝑦𝐶)) ↔ ((𝑥𝐴𝑦𝐵) ∨ (𝑥𝐴𝑦𝐶)))
86, 7bitri 183 . . . . 5 ((𝑥𝐴𝑦 ∈ (𝐵𝐶)) ↔ ((𝑥𝐴𝑦𝐵) ∨ (𝑥𝐴𝑦𝐶)))
98opabbii 3963 . . . 4 {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦 ∈ (𝐵𝐶))} = {⟨𝑥, 𝑦⟩ ∣ ((𝑥𝐴𝑦𝐵) ∨ (𝑥𝐴𝑦𝐶))}
10 unopab 3975 . . . 4 ({⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐵)} ∪ {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)}) = {⟨𝑥, 𝑦⟩ ∣ ((𝑥𝐴𝑦𝐵) ∨ (𝑥𝐴𝑦𝐶))}
119, 10eqtr4i 2139 . . 3 {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦 ∈ (𝐵𝐶))} = ({⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐵)} ∪ {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)})
124, 11eqtr4i 2139 . 2 ((𝐴 × 𝐵) ∪ (𝐴 × 𝐶)) = {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦 ∈ (𝐵𝐶))}
131, 12eqtr4i 2139 1 (𝐴 × (𝐵𝐶)) = ((𝐴 × 𝐵) ∪ (𝐴 × 𝐶))
Colors of variables: wff set class
Syntax hints:  wa 103  wo 680   = wceq 1314  wcel 1463  cun 3037  {copab 3956   × cxp 4505
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 681  ax-5 1406  ax-7 1407  ax-gen 1408  ax-ie1 1452  ax-ie2 1453  ax-8 1465  ax-10 1466  ax-11 1467  ax-i12 1468  ax-bndl 1469  ax-4 1470  ax-17 1489  ax-i9 1493  ax-ial 1497  ax-i5r 1498  ax-ext 2097
This theorem depends on definitions:  df-bi 116  df-tru 1317  df-nf 1420  df-sb 1719  df-clab 2102  df-cleq 2108  df-clel 2111  df-nfc 2245  df-v 2660  df-un 3043  df-opab 3958  df-xp 4513
This theorem is referenced by:  xpun  4568  djuassen  7037  xpdjuen  7038
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