Theorem basis1 14490

Description: Property of a basis. (Contributed by NM, 16-Jul-2006.)

Assertion

Ref	Expression
basis1	|- ( ( B e. TopBases /\ C e. B /\ D e. B ) -> ( C i^i D ) C_ U. ( B i^i ~P ( C i^i D ) ) )

Proof of Theorem basis1

Dummy variables x y are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		isbasisg 14487	. . . 4 |- ( B e. TopBases -> ( B e. TopBases <-> A. x e. B A. y e. B ( x i^i y ) C_ U. ( B i^i ~P ( x i^i y ) ) ) )
2	1	ibi 176	. . 3 |- ( B e. TopBases -> A. x e. B A. y e. B ( x i^i y ) C_ U. ( B i^i ~P ( x i^i y ) ) )
3		ineq1 3366	. . . . 5 |- ( x = C -> ( x i^i y ) = ( C i^i y ) )
4	3	pweqd 3620	. . . . . . 7 |- ( x = C -> ~P ( x i^i y ) = ~P ( C i^i y ) )
5	4	ineq2d 3373	. . . . . 6 |- ( x = C -> ( B i^i ~P ( x i^i y ) ) = ( B i^i ~P ( C i^i y ) ) )
6	5	unieqd 3860	. . . . 5 |- ( x = C -> U. ( B i^i ~P ( x i^i y ) ) = U. ( B i^i ~P ( C i^i y ) ) )
7	3, 6	sseq12d 3223	. . . 4 |- ( x = C -> ( ( x i^i y ) C_ U. ( B i^i ~P ( x i^i y ) ) <-> ( C i^i y ) C_ U. ( B i^i ~P ( C i^i y ) ) ) )
8		ineq2 3367	. . . . 5 |- ( y = D -> ( C i^i y ) = ( C i^i D ) )
9	8	pweqd 3620	. . . . . . 7 |- ( y = D -> ~P ( C i^i y ) = ~P ( C i^i D ) )
10	9	ineq2d 3373	. . . . . 6 |- ( y = D -> ( B i^i ~P ( C i^i y ) ) = ( B i^i ~P ( C i^i D ) ) )
11	10	unieqd 3860	. . . . 5 |- ( y = D -> U. ( B i^i ~P ( C i^i y ) ) = U. ( B i^i ~P ( C i^i D ) ) )
12	8, 11	sseq12d 3223	. . . 4 |- ( y = D -> ( ( C i^i y ) C_ U. ( B i^i ~P ( C i^i y ) ) <-> ( C i^i D ) C_ U. ( B i^i ~P ( C i^i D ) ) ) )
13	7, 12	rspc2v 2889	. . 3 |- ( ( C e. B /\ D e. B ) -> ( A. x e. B A. y e. B ( x i^i y ) C_ U. ( B i^i ~P ( x i^i y ) ) -> ( C i^i D ) C_ U. ( B i^i ~P ( C i^i D ) ) ) )
14	2, 13	syl5com 29	. 2 |- ( B e. TopBases -> ( ( C e. B /\ D e. B ) -> ( C i^i D ) C_ U. ( B i^i ~P ( C i^i D ) ) ) )
15	14	3impib 1203	1 |- ( ( B e. TopBases /\ C e. B /\ D e. B ) -> ( C i^i D ) C_ U. ( B i^i ~P ( C i^i D ) ) )

Syntax hints:   -> wi 4   /\ wa 104   /\ w3a 980   = wceq 1372   e. wcel 2175   A.wral 2483   i^i cin 3164   C_ wss 3165   ~Pcpw 3615   U.cuni 3849   TopBasesctb 14485

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 710  ax-5 1469  ax-7 1470  ax-gen 1471  ax-ie1 1515  ax-ie2 1516  ax-8 1526  ax-10 1527  ax-11 1528  ax-i12 1529  ax-bndl 1531  ax-4 1532  ax-17 1548  ax-i9 1552  ax-ial 1556  ax-i5r 1557  ax-ext 2186

This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1375  df-nf 1483  df-sb 1785  df-clab 2191  df-cleq 2197  df-clel 2200  df-nfc 2336  df-ral 2488  df-rex 2489  df-v 2773  df-in 3171  df-ss 3178  df-pw 3617  df-uni 3850  df-bases 14486

This theorem is referenced by: (None)