Theorem cnss2 21081

Description: If the topology K is finer than J, then there are fewer continuous functions into K than into J from some other space. (Contributed by Mario Carneiro, 19-Mar-2015.) (Revised by Mario Carneiro, 21-Aug-2015.)

Hypothesis

Ref	Expression
cnss2.1	|- Y = U. K

Assertion

Ref	Expression
cnss2	|- ( ( L e. (TopOn ` Y ) /\ L C_ K ) -> ( J Cn K ) C_ ( J Cn L ) )

Proof of Theorem cnss2

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

Step	Hyp	Ref	Expression
1		eqid 2622	. . . . . 6 |- U. J = U. J
2		cnss2.1	. . . . . 6 |- Y = U. K
3	1, 2	cnf 21050	. . . . 5 |- ( f e. ( J Cn K ) -> f : U. J --> Y )
4	3	adantl 482	. . . 4 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> f : U. J --> Y )
5		simplr 792	. . . . 5 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> L C_ K )
6		cnima 21069	. . . . . . 7 |- ( ( f e. ( J Cn K ) /\ x e. K ) -> ( `' f " x ) e. J )
7	6	ralrimiva 2966	. . . . . 6 |- ( f e. ( J Cn K ) -> A. x e. K ( `' f " x ) e. J )
8	7	adantl 482	. . . . 5 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> A. x e. K ( `' f " x ) e. J )
9		ssralv 3666	. . . . 5 |- ( L C_ K -> ( A. x e. K ( `' f " x ) e. J -> A. x e. L ( `' f " x ) e. J ) )
10	5, 8, 9	sylc 65	. . . 4 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> A. x e. L ( `' f " x ) e. J )
11		cntop1 21044	. . . . . . 7 |- ( f e. ( J Cn K ) -> J e. Top )
12	11	adantl 482	. . . . . 6 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> J e. Top )
13	1	toptopon 20722	. . . . . 6 |- ( J e. Top <-> J e. (TopOn ` U. J ) )
14	12, 13	sylib 208	. . . . 5 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> J e. (TopOn ` U. J ) )
15		simpll 790	. . . . 5 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> L e. (TopOn ` Y ) )
16		iscn 21039	. . . . 5 |- ( ( J e. (TopOn ` U. J ) /\ L e. (TopOn ` Y ) ) -> ( f e. ( J Cn L ) <-> ( f : U. J --> Y /\ A. x e. L ( `' f " x ) e. J ) ) )
17	14, 15, 16	syl2anc 693	. . . 4 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> ( f e. ( J Cn L ) <-> ( f : U. J --> Y /\ A. x e. L ( `' f " x ) e. J ) ) )
18	4, 10, 17	mpbir2and 957	. . 3 |- ( ( ( L e. (TopOn ` Y ) /\ L C_ K ) /\ f e. ( J Cn K ) ) -> f e. ( J Cn L ) )
19	18	ex 450	. 2 |- ( ( L e. (TopOn ` Y ) /\ L C_ K ) -> ( f e. ( J Cn K ) -> f e. ( J Cn L ) ) )
20	19	ssrdv 3609	1 |- ( ( L e. (TopOn ` Y ) /\ L C_ K ) -> ( J Cn K ) C_ ( J Cn L ) )

Syntax hints:   -> wi 4   <-> wb 196   /\ wa 384   = wceq 1483   e. wcel 1990   A.wral 2912   C_ wss 3574   U.cuni 4436   `'ccnv 5113   "cima 5117   -->wf 5884   ` cfv 5888  (class class class)co 6650   Topctop 20698  TopOnctopon 20715   Cn ccn 21028

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-8 1992  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-sep 4781  ax-nul 4789  ax-pow 4843  ax-pr 4906  ax-un 6949

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-eu 2474  df-mo 2475  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-ral 2917  df-rex 2918  df-rab 2921  df-v 3202  df-sbc 3436  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-if 4087  df-pw 4160  df-sn 4178  df-pr 4180  df-op 4184  df-uni 4437  df-br 4654  df-opab 4713  df-mpt 4730  df-id 5024  df-xp 5120  df-rel 5121  df-cnv 5122  df-co 5123  df-dm 5124  df-rn 5125  df-res 5126  df-ima 5127  df-iota 5851  df-fun 5890  df-fn 5891  df-f 5892  df-fv 5896  df-ov 6653  df-oprab 6654  df-mpt2 6655  df-map 7859  df-top 20699  df-topon 20716  df-cn 21031

This theorem is referenced by:  kgencn3  21361  xmetdcn  22641