Theorem indi 3873

Description: Distributive law for intersection over union. Exercise 10 of [TakeutiZaring] p. 17. (Contributed by NM, 30-Sep-2002.) (Proof shortened by Andrew Salmon, 26-Jun-2011.)

Assertion

Ref	Expression
indi	|- ( A i^i ( B u. C ) ) = ( ( A i^i B ) u. ( A i^i C ) )

Proof of Theorem indi

Dummy variable x is distinct from all other variables.

Step	Hyp	Ref	Expression
1		andi 911	. . . 4 |- ( ( x e. A /\ ( x e. B \/ x e. C ) ) <-> ( ( x e. A /\ x e. B ) \/ ( x e. A /\ x e. C ) ) )
2		elin 3796	. . . . 5 |- ( x e. ( A i^i B ) <-> ( x e. A /\ x e. B ) )
3		elin 3796	. . . . 5 |- ( x e. ( A i^i C ) <-> ( x e. A /\ x e. C ) )
4	2, 3	orbi12i 543	. . . 4 |- ( ( x e. ( A i^i B ) \/ x e. ( A i^i C ) ) <-> ( ( x e. A /\ x e. B ) \/ ( x e. A /\ x e. C ) ) )
5	1, 4	bitr4i 267	. . 3 |- ( ( x e. A /\ ( x e. B \/ x e. C ) ) <-> ( x e. ( A i^i B ) \/ x e. ( A i^i C ) ) )
6		elun 3753	. . . 4 |- ( x e. ( B u. C ) <-> ( x e. B \/ x e. C ) )
7	6	anbi2i 730	. . 3 |- ( ( x e. A /\ x e. ( B u. C ) ) <-> ( x e. A /\ ( x e. B \/ x e. C ) ) )
8		elun 3753	. . 3 |- ( x e. ( ( A i^i B ) u. ( A i^i C ) ) <-> ( x e. ( A i^i B ) \/ x e. ( A i^i C ) ) )
9	5, 7, 8	3bitr4i 292	. 2 |- ( ( x e. A /\ x e. ( B u. C ) ) <-> x e. ( ( A i^i B ) u. ( A i^i C ) ) )
10	9	ineqri 3806	1 |- ( A i^i ( B u. C ) ) = ( ( A i^i B ) u. ( A i^i C ) )

Syntax hints:   \/ wo 383   /\ wa 384   = wceq 1483   e. wcel 1990   u. cun 3572   i^i cin 3573

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-v 3202  df-un 3579  df-in 3581

This theorem is referenced by:  indir  3875  difindi  3881  undisj2  4030  disjssun  4036  difdifdir  4056  disjpr2  4248  disjpr2OLD  4249  diftpsn3OLD  4333  resundi  5410  fresaun  6075  elfiun  8336  unxpwdom  8494  kmlem2  8973  cdainf  9014  ackbij1lem1  9042  ackbij1lem2  9043  ssxr  10107  incexclem  14568  bitsinv1  15164  bitsinvp1  15171  bitsres  15195  paste  21098  unmbl  23305  ovolioo  23336  uniioombllem4  23354  volcn  23374  ellimc2  23641  lhop2  23778  ex-in  27282  eulerpartgbij  30434  poimirlem3  33412  poimirlem15  33424  asindmre  33495  iunrelexp0  37994  sge0resplit  40623  sge0split  40626