Theorem xpundir 3226

Description: Distributive law for cross product over union. Similar to Theorem 103 of [Suppes] p. 52.

Assertion

Ref	Expression
xpundir	|- ((A u. B) X. C) = ((A X. C) u. (B X. C))

Proof of Theorem xpundir

Step	Hyp	Ref	Expression
1		elun 2173	. . . . . 6 |- (x e. (A u. B) <-> (x e. A \/ x e. B))
2	1	anbi1i 481	. . . . 5 |- ((x e. (A u. B) /\ y e. C) <-> ((x e. A \/ x e. B) /\ y e. C))
3		andir 605	. . . . 5 |- (((x e. A \/ x e. B) /\ y e. C) <-> ((x e. A /\ y e. C) \/ (x e. B /\ y e. C)))
4	2, 3	bitr 173	. . . 4 |- ((x e. (A u. B) /\ y e. C) <-> ((x e. A /\ y e. C) \/ (x e. B /\ y e. C)))
5	4	opabbii 2671	. . 3 |- {<.x, y>. | (x e. (A u. B) /\ y e. C)} = {<.x, y>. | ((x e. A /\ y e. C) \/ (x e. B /\ y e. C))}
6		unopab 2679	. . 3 |- ({<.x, y>. | (x e. A /\ y e. C)} u. {<.x, y>. | (x e. B /\ y e. C)}) = {<.x, y>. | ((x e. A /\ y e. C) \/ (x e. B /\ y e. C))}
7	5, 6	eqtr4 1498	. 2 |- {<.x, y>. | (x e. (A u. B) /\ y e. C)} = ({<.x, y>. | (x e. A /\ y e. C)} u. {<.x, y>. | (x e. B /\ y e. C)})
8		df-xp 3184	. 2 |- ((A u. B) X. C) = {<.x, y>. | (x e. (A u. B) /\ y e. C)}
9		df-xp 3184	. . 3 |- (A X. C) = {<.x, y>. | (x e. A /\ y e. C)}
10		df-xp 3184	. . 3 |- (B X. C) = {<.x, y>. | (x e. B /\ y e. C)}
11	9, 10	uneq12i 2182	. 2 |- ((A X. C) u. (B X. C)) = ({<.x, y>. | (x e. A /\ y e. C)} u. {<.x, y>. | (x e. B /\ y e. C)})
12	7, 8, 11	3eqtr4 1505	1 |- ((A u. B) X. C) = ((A X. C) u. (B X. C))

Syntax hints:   \/ wo 222   /\ wa 223   = wceq 956   e. wcel 958   u. cun 2045  {copab 2666   X. cxp 3168

This theorem is referenced by:  xpun 3227  resundi 3378  cdaassen 4930

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 962  ax-gen 963  ax-8 964  ax-10 966  ax-12 968  ax-17 971  ax-4 973  ax-5o 975  ax-6o 978  ax-9o 1123  ax-10o 1140  ax-16 1210  ax-11o 1218  ax-ext 1459

This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-ex 981  df-sb 1172  df-clab 1464  df-cleq 1469  df-clel 1472  df-v 1812  df-un 2050  df-opab 2667  df-xp 3184

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