MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  disjpr2 Structured version   Visualization version   GIF version

Theorem disjpr2 4406
Description: Two completely distinct unordered pairs are disjoint. (Contributed by Alexander van der Vekens, 11-Nov-2017.) (Proof shortened by JJ, 23-Jul-2021.)
Assertion
Ref Expression
disjpr2 (((𝐴𝐶𝐵𝐶) ∧ (𝐴𝐷𝐵𝐷)) → ({𝐴, 𝐵} ∩ {𝐶, 𝐷}) = ∅)

Proof of Theorem disjpr2
StepHypRef Expression
1 df-pr 4339 . . . 4 {𝐶, 𝐷} = ({𝐶} ∪ {𝐷})
21ineq2i 3975 . . 3 ({𝐴, 𝐵} ∩ {𝐶, 𝐷}) = ({𝐴, 𝐵} ∩ ({𝐶} ∪ {𝐷}))
3 indi 4040 . . 3 ({𝐴, 𝐵} ∩ ({𝐶} ∪ {𝐷})) = (({𝐴, 𝐵} ∩ {𝐶}) ∪ ({𝐴, 𝐵} ∩ {𝐷}))
42, 3eqtri 2787 . 2 ({𝐴, 𝐵} ∩ {𝐶, 𝐷}) = (({𝐴, 𝐵} ∩ {𝐶}) ∪ ({𝐴, 𝐵} ∩ {𝐷}))
5 df-pr 4339 . . . . . . . 8 {𝐴, 𝐵} = ({𝐴} ∪ {𝐵})
65ineq1i 3974 . . . . . . 7 ({𝐴, 𝐵} ∩ {𝐶}) = (({𝐴} ∪ {𝐵}) ∩ {𝐶})
7 indir 4042 . . . . . . 7 (({𝐴} ∪ {𝐵}) ∩ {𝐶}) = (({𝐴} ∩ {𝐶}) ∪ ({𝐵} ∩ {𝐶}))
86, 7eqtri 2787 . . . . . 6 ({𝐴, 𝐵} ∩ {𝐶}) = (({𝐴} ∩ {𝐶}) ∪ ({𝐵} ∩ {𝐶}))
9 disjsn2 4405 . . . . . . . 8 (𝐴𝐶 → ({𝐴} ∩ {𝐶}) = ∅)
10 disjsn2 4405 . . . . . . . 8 (𝐵𝐶 → ({𝐵} ∩ {𝐶}) = ∅)
119, 10anim12i 606 . . . . . . 7 ((𝐴𝐶𝐵𝐶) → (({𝐴} ∩ {𝐶}) = ∅ ∧ ({𝐵} ∩ {𝐶}) = ∅))
12 un00 4175 . . . . . . 7 ((({𝐴} ∩ {𝐶}) = ∅ ∧ ({𝐵} ∩ {𝐶}) = ∅) ↔ (({𝐴} ∩ {𝐶}) ∪ ({𝐵} ∩ {𝐶})) = ∅)
1311, 12sylib 209 . . . . . 6 ((𝐴𝐶𝐵𝐶) → (({𝐴} ∩ {𝐶}) ∪ ({𝐵} ∩ {𝐶})) = ∅)
148, 13syl5eq 2811 . . . . 5 ((𝐴𝐶𝐵𝐶) → ({𝐴, 𝐵} ∩ {𝐶}) = ∅)
1514adantr 472 . . . 4 (((𝐴𝐶𝐵𝐶) ∧ (𝐴𝐷𝐵𝐷)) → ({𝐴, 𝐵} ∩ {𝐶}) = ∅)
165ineq1i 3974 . . . . . . 7 ({𝐴, 𝐵} ∩ {𝐷}) = (({𝐴} ∪ {𝐵}) ∩ {𝐷})
17 indir 4042 . . . . . . 7 (({𝐴} ∪ {𝐵}) ∩ {𝐷}) = (({𝐴} ∩ {𝐷}) ∪ ({𝐵} ∩ {𝐷}))
1816, 17eqtri 2787 . . . . . 6 ({𝐴, 𝐵} ∩ {𝐷}) = (({𝐴} ∩ {𝐷}) ∪ ({𝐵} ∩ {𝐷}))
19 disjsn2 4405 . . . . . . . 8 (𝐴𝐷 → ({𝐴} ∩ {𝐷}) = ∅)
20 disjsn2 4405 . . . . . . . 8 (𝐵𝐷 → ({𝐵} ∩ {𝐷}) = ∅)
2119, 20anim12i 606 . . . . . . 7 ((𝐴𝐷𝐵𝐷) → (({𝐴} ∩ {𝐷}) = ∅ ∧ ({𝐵} ∩ {𝐷}) = ∅))
22 un00 4175 . . . . . . 7 ((({𝐴} ∩ {𝐷}) = ∅ ∧ ({𝐵} ∩ {𝐷}) = ∅) ↔ (({𝐴} ∩ {𝐷}) ∪ ({𝐵} ∩ {𝐷})) = ∅)
2321, 22sylib 209 . . . . . 6 ((𝐴𝐷𝐵𝐷) → (({𝐴} ∩ {𝐷}) ∪ ({𝐵} ∩ {𝐷})) = ∅)
2418, 23syl5eq 2811 . . . . 5 ((𝐴𝐷𝐵𝐷) → ({𝐴, 𝐵} ∩ {𝐷}) = ∅)
2524adantl 473 . . . 4 (((𝐴𝐶𝐵𝐶) ∧ (𝐴𝐷𝐵𝐷)) → ({𝐴, 𝐵} ∩ {𝐷}) = ∅)
2615, 25uneq12d 3932 . . 3 (((𝐴𝐶𝐵𝐶) ∧ (𝐴𝐷𝐵𝐷)) → (({𝐴, 𝐵} ∩ {𝐶}) ∪ ({𝐴, 𝐵} ∩ {𝐷})) = (∅ ∪ ∅))
27 un0 4131 . . 3 (∅ ∪ ∅) = ∅
2826, 27syl6eq 2815 . 2 (((𝐴𝐶𝐵𝐶) ∧ (𝐴𝐷𝐵𝐷)) → (({𝐴, 𝐵} ∩ {𝐶}) ∪ ({𝐴, 𝐵} ∩ {𝐷})) = ∅)
294, 28syl5eq 2811 1 (((𝐴𝐶𝐵𝐶) ∧ (𝐴𝐷𝐵𝐷)) → ({𝐴, 𝐵} ∩ {𝐶, 𝐷}) = ∅)
Colors of variables: wff setvar class
Syntax hints:  wi 4  wa 384   = wceq 1652  wne 2937  cun 3732  cin 3733  c0 4081  {csn 4336  {cpr 4338
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1890  ax-4 1904  ax-5 2005  ax-6 2070  ax-7 2105  ax-9 2164  ax-10 2183  ax-11 2198  ax-12 2211  ax-ext 2743
This theorem depends on definitions:  df-bi 198  df-an 385  df-or 874  df-tru 1656  df-ex 1875  df-nf 1879  df-sb 2063  df-clab 2752  df-cleq 2758  df-clel 2761  df-nfc 2896  df-ne 2938  df-ral 3060  df-v 3352  df-dif 3737  df-un 3739  df-in 3741  df-ss 3748  df-nul 4082  df-sn 4337  df-pr 4339
This theorem is referenced by:  disjprsn  4407  disjtp2  4409  funcnvqp  6133
  Copyright terms: Public domain W3C validator