ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  xpundir GIF version

Theorem xpundir 4424
Description: Distributive law for cross product over union. Similar to Theorem 103 of [Suppes] p. 52. (Contributed by NM, 30-Sep-2002.)
Assertion
Ref Expression
xpundir ((𝐴𝐵) × 𝐶) = ((𝐴 × 𝐶) ∪ (𝐵 × 𝐶))

Proof of Theorem xpundir
Dummy variables 𝑥 𝑦 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 df-xp 4378 . 2 ((𝐴𝐵) × 𝐶) = {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ (𝐴𝐵) ∧ 𝑦𝐶)}
2 df-xp 4378 . . . 4 (𝐴 × 𝐶) = {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)}
3 df-xp 4378 . . . 4 (𝐵 × 𝐶) = {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐵𝑦𝐶)}
42, 3uneq12i 3122 . . 3 ((𝐴 × 𝐶) ∪ (𝐵 × 𝐶)) = ({⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)} ∪ {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐵𝑦𝐶)})
5 elun 3111 . . . . . . 7 (𝑥 ∈ (𝐴𝐵) ↔ (𝑥𝐴𝑥𝐵))
65anbi1i 439 . . . . . 6 ((𝑥 ∈ (𝐴𝐵) ∧ 𝑦𝐶) ↔ ((𝑥𝐴𝑥𝐵) ∧ 𝑦𝐶))
7 andir 743 . . . . . 6 (((𝑥𝐴𝑥𝐵) ∧ 𝑦𝐶) ↔ ((𝑥𝐴𝑦𝐶) ∨ (𝑥𝐵𝑦𝐶)))
86, 7bitri 177 . . . . 5 ((𝑥 ∈ (𝐴𝐵) ∧ 𝑦𝐶) ↔ ((𝑥𝐴𝑦𝐶) ∨ (𝑥𝐵𝑦𝐶)))
98opabbii 3851 . . . 4 {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ (𝐴𝐵) ∧ 𝑦𝐶)} = {⟨𝑥, 𝑦⟩ ∣ ((𝑥𝐴𝑦𝐶) ∨ (𝑥𝐵𝑦𝐶))}
10 unopab 3863 . . . 4 ({⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)} ∪ {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐵𝑦𝐶)}) = {⟨𝑥, 𝑦⟩ ∣ ((𝑥𝐴𝑦𝐶) ∨ (𝑥𝐵𝑦𝐶))}
119, 10eqtr4i 2079 . . 3 {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ (𝐴𝐵) ∧ 𝑦𝐶)} = ({⟨𝑥, 𝑦⟩ ∣ (𝑥𝐴𝑦𝐶)} ∪ {⟨𝑥, 𝑦⟩ ∣ (𝑥𝐵𝑦𝐶)})
124, 11eqtr4i 2079 . 2 ((𝐴 × 𝐶) ∪ (𝐵 × 𝐶)) = {⟨𝑥, 𝑦⟩ ∣ (𝑥 ∈ (𝐴𝐵) ∧ 𝑦𝐶)}
131, 12eqtr4i 2079 1 ((𝐴𝐵) × 𝐶) = ((𝐴 × 𝐶) ∪ (𝐵 × 𝐶))
Colors of variables: wff set class
Syntax hints:  wa 101  wo 639   = wceq 1259  wcel 1409  cun 2942  {copab 3844   × cxp 4370
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-io 640  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-10 1412  ax-11 1413  ax-i12 1414  ax-bndl 1415  ax-4 1416  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038
This theorem depends on definitions:  df-bi 114  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-v 2576  df-un 2949  df-opab 3846  df-xp 4378
This theorem is referenced by:  xpun  4428  resundi  4652
  Copyright terms: Public domain W3C validator