Theorem cndis 19013

Description: Every function is continuous when the domain is discrete. (Contributed by Mario Carneiro, 19-Mar-2015.) (Revised by Mario Carneiro, 21-Aug-2015.)

Assertion

Ref	Expression
cndis	|- ( ( A e. V /\ J e. (TopOn ` X ) ) -> ( ~P A Cn J ) = ( X ^m A ) )

Proof of Theorem cndis

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

Step	Hyp	Ref	Expression
1		cnvimass 5289	. . . . . . . 8 |- ( `' f " x ) C_ dom f
2		fdm 5663	. . . . . . . . 9 |- ( f : A --> X -> dom f = A )
3	2	adantl 466	. . . . . . . 8 |- ( ( ( A e. V /\ J e. (TopOn ` X ) ) /\ f : A --> X ) -> dom f = A )
4	1, 3	syl5sseq 3504	. . . . . . 7 |- ( ( ( A e. V /\ J e. (TopOn ` X ) ) /\ f : A --> X ) -> ( `' f " x ) C_ A )
5		elpw2g 4555	. . . . . . . 8 |- ( A e. V -> ( ( `' f " x ) e. ~P A <-> ( `' f " x ) C_ A ) )
6	5	ad2antrr 725	. . . . . . 7 |- ( ( ( A e. V /\ J e. (TopOn ` X ) ) /\ f : A --> X ) -> ( ( `' f " x ) e. ~P A <-> ( `' f " x ) C_ A ) )
7	4, 6	mpbird 232	. . . . . 6 |- ( ( ( A e. V /\ J e. (TopOn ` X ) ) /\ f : A --> X ) -> ( `' f " x ) e. ~P A )
8	7	ralrimivw 2823	. . . . 5 |- ( ( ( A e. V /\ J e. (TopOn ` X ) ) /\ f : A --> X ) -> A. x e. J ( `' f " x ) e. ~P A )
9	8	ex 434	. . . 4 |- ( ( A e. V /\ J e. (TopOn ` X ) ) -> ( f : A --> X -> A. x e. J ( `' f " x ) e. ~P A ) )
10	9	pm4.71d 634	. . 3 |- ( ( A e. V /\ J e. (TopOn ` X ) ) -> ( f : A --> X <-> ( f : A --> X /\ A. x e. J ( `' f " x ) e. ~P A ) ) )
11		toponmax 18651	. . . 4 |- ( J e. (TopOn ` X ) -> X e. J )
12		id 22	. . . 4 |- ( A e. V -> A e. V )
13		elmapg 7329	. . . 4 |- ( ( X e. J /\ A e. V ) -> ( f e. ( X ^m A ) <-> f : A --> X ) )
14	11, 12, 13	syl2anr 478	. . 3 |- ( ( A e. V /\ J e. (TopOn ` X ) ) -> ( f e. ( X ^m A ) <-> f : A --> X ) )
15		distopon 18719	. . . 4 |- ( A e. V -> ~P A e. (TopOn ` A ) )
16		iscn 18957	. . . 4 |- ( ( ~P A e. (TopOn ` A ) /\ J e. (TopOn ` X ) ) -> ( f e. ( ~P A Cn J ) <-> ( f : A --> X /\ A. x e. J ( `' f " x ) e. ~P A ) ) )
17	15, 16	sylan 471	. . 3 |- ( ( A e. V /\ J e. (TopOn ` X ) ) -> ( f e. ( ~P A Cn J ) <-> ( f : A --> X /\ A. x e. J ( `' f " x ) e. ~P A ) ) )
18	10, 14, 17	3bitr4rd 286	. 2 |- ( ( A e. V /\ J e. (TopOn ` X ) ) -> ( f e. ( ~P A Cn J ) <-> f e. ( X ^m A ) ) )
19	18	eqrdv 2448	1 |- ( ( A e. V /\ J e. (TopOn ` X ) ) -> ( ~P A Cn J ) = ( X ^m A ) )

Syntax hints:   -> wi 4   <-> wb 184   /\ wa 369   = wceq 1370   e. wcel 1758   A.wral 2795   C_ wss 3428   ~Pcpw 3960   `'ccnv 4939   dom cdm 4940   "cima 4943   -->wf 5514   ` cfv 5518  (class class class)co 6192   ^m cmap 7316  TopOnctopon 18617   Cn ccn 18946

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1592  ax-4 1603  ax-5 1671  ax-6 1710  ax-7 1730  ax-8 1760  ax-9 1762  ax-10 1777  ax-11 1782  ax-12 1794  ax-13 1952  ax-ext 2430  ax-sep 4513  ax-nul 4521  ax-pow 4570  ax-pr 4631  ax-un 6474

This theorem depends on definitions:  df-bi 185  df-or 370  df-an 371  df-3an 967  df-tru 1373  df-ex 1588  df-nf 1591  df-sb 1703  df-eu 2264  df-mo 2265  df-clab 2437  df-cleq 2443  df-clel 2446  df-nfc 2601  df-ne 2646  df-ral 2800  df-rex 2801  df-rab 2804  df-v 3072  df-sbc 3287  df-dif 3431  df-un 3433  df-in 3435  df-ss 3442  df-nul 3738  df-if 3892  df-pw 3962  df-sn 3978  df-pr 3980  df-op 3984  df-uni 4192  df-br 4393  df-opab 4451  df-mpt 4452  df-id 4736  df-xp 4946  df-rel 4947  df-cnv 4948  df-co 4949  df-dm 4950  df-rn 4951  df-res 4952  df-ima 4953  df-iota 5481  df-fun 5520  df-fn 5521  df-f 5522  df-fv 5526  df-ov 6195  df-oprab 6196  df-mpt2 6197  df-map 7318  df-top 18621  df-topon 18624  df-cn 18949

This theorem is referenced by:  xkopt  19346  distgp  19788  symgtgp  19790