Theorem topgele 15020

Description: The topologies over the same set have the greatest element (the discrete topology) and the least element (the indiscrete topology). (Contributed by FL, 18-Apr-2010.) (Revised by Mario Carneiro, 16-Sep-2015.)

Assertion

Ref	Expression
topgele	|- ( J e. (TopOn ` X ) -> ( { (/) , X } C_ J /\ J C_ ~P X ) )

Proof of Theorem topgele

Step	Hyp	Ref	Expression
1		topontop 15005	. . . 4 |- ( J e. (TopOn ` X ) -> J e. Top )
2		0opn 14997	. . . 4 |- ( J e. Top -> (/) e. J )
3	1, 2	syl 14	. . 3 |- ( J e. (TopOn ` X ) -> (/) e. J )
4		toponmax 15016	. . 3 |- ( J e. (TopOn ` X ) -> X e. J )
5		0ex 4242	. . . 4 |- (/) e. _V
6		prssg 3856	. . . 4 |- ( ( (/) e. _V /\ X e. J ) -> ( ( (/) e. J /\ X e. J ) <-> { (/) , X } C_ J ) )
7	5, 4, 6	sylancr 414	. . 3 |- ( J e. (TopOn ` X ) -> ( ( (/) e. J /\ X e. J ) <-> { (/) , X } C_ J ) )
8	3, 4, 7	mpbi2and 952	. 2 |- ( J e. (TopOn ` X ) -> { (/) , X } C_ J )
9		toponuni 15006	. . . 4 |- ( J e. (TopOn ` X ) -> X = U. J )
10		eqimss2 3297	. . . 4 |- ( X = U. J -> U. J C_ X )
11	9, 10	syl 14	. . 3 |- ( J e. (TopOn ` X ) -> U. J C_ X )
12		sspwuni 4081	. . 3 |- ( J C_ ~P X <-> U. J C_ X )
13	11, 12	sylibr 134	. 2 |- ( J e. (TopOn ` X ) -> J C_ ~P X )
14	8, 13	jca 306	1 |- ( J e. (TopOn ` X ) -> ( { (/) , X } C_ J /\ J C_ ~P X ) )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   = wceq 1398   e. wcel 2205   _Vcvv 2815   C_ wss 3214   (/)c0 3512   ~Pcpw 3674   {cpr 3695   U.cuni 3919   ` cfv 5357   Topctop 14988  TopOnctopon 15001

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-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2207  ax-14 2208  ax-ext 2216  ax-sep 4233  ax-nul 4241  ax-pow 4292  ax-pr 4327  ax-un 4559

This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-fal 1404  df-nf 1510  df-sb 1812  df-eu 2085  df-mo 2086  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-ral 2527  df-rex 2528  df-rab 2531  df-v 2817  df-sbc 3046  df-dif 3216  df-un 3218  df-in 3220  df-ss 3227  df-nul 3513  df-pw 3676  df-sn 3700  df-pr 3701  df-op 3703  df-uni 3920  df-br 4115  df-opab 4177  df-mpt 4178  df-id 4419  df-xp 4760  df-rel 4761  df-cnv 4762  df-co 4763  df-dm 4764  df-iota 5317  df-fun 5359  df-fv 5365  df-top 14989  df-topon 15002

This theorem is referenced by: (None)