Theorem exmidexmid 4314

Description: EXMID implies that an arbitrary proposition is decidable. That is, EXMID captures the usual meaning of excluded middle when stated in terms of propositions.

To get other propositional statements which are equivalent to excluded middle, combine this with notnotrdc 851, peircedc 922, or condc 861.

(Contributed by Jim Kingdon, 18-Jun-2022.)

Assertion

Ref	Expression
exmidexmid	|- (EXMID -> DECID ph )

Proof of Theorem exmidexmid

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

Step	Hyp	Ref	Expression
1		ssrab2 3327	. . 3 |- { z e. { (/) } | ph } C_ { (/) }
2		df-exmid 4313	. . . 4 |- (EXMID <-> A. x ( x C_ { (/) } -> DECID (/) e. x ) )
3		p0ex 4306	. . . . . 6 |- { (/) } e. _V
4	3	rabex 4261	. . . . 5 |- { z e. { (/) } | ph } e. _V
5		sseq1 3265	. . . . . 6 |- ( x = { z e. { (/) } | ph } -> ( x C_ { (/) } <-> { z e. { (/) } | ph } C_ { (/) } ) )
6		eleq2 2298	. . . . . . 7 |- ( x = { z e. { (/) } | ph } -> ( (/) e. x <-> (/) e. { z e. { (/) } | ph } ) )
7	6	dcbid 846	. . . . . 6 |- ( x = { z e. { (/) } | ph } -> (DECID (/) e. x <-> DECID (/) e. { z e. { (/) } | ph } ) )
8	5, 7	imbi12d 234	. . . . 5 |- ( x = { z e. { (/) } | ph } -> ( ( x C_ { (/) } -> DECID (/) e. x ) <-> ( { z e. { (/) } | ph } C_ { (/) } -> DECID (/) e. { z e. { (/) } | ph } ) ) )
9	4, 8	spcv 2913	. . . 4 |- ( A. x ( x C_ { (/) } -> DECID (/) e. x ) -> ( { z e. { (/) } | ph } C_ { (/) } -> DECID (/) e. { z e. { (/) } | ph } ) )
10	2, 9	sylbi 121	. . 3 |- (EXMID -> ( { z e. { (/) } | ph } C_ { (/) } -> DECID (/) e. { z e. { (/) } | ph } ) )
11	1, 10	mpi 15	. 2 |- (EXMID -> DECID (/) e. { z e. { (/) } | ph } )
12		0ex 4242	. . . . 5 |- (/) e. _V
13	12	snid 3725	. . . 4 |- (/) e. { (/) }
14		biidd 172	. . . . 5 |- ( z = (/) -> ( ph <-> ph ) )
15	14	elrab 2976	. . . 4 |- ( (/) e. { z e. { (/) } | ph } <-> ( (/) e. { (/) } /\ ph ) )
16	13, 15	mpbiran 949	. . 3 |- ( (/) e. { z e. { (/) } | ph } <-> ph )
17	16	dcbii 848	. 2 |- (DECID (/) e. { z e. { (/) } | ph } <-> DECID ph )
18	11, 17	sylib 122	1 |- (EXMID -> DECID ph )

Syntax hints:   -> wi 4  DECID wdc 842   A.wal 1396   = wceq 1398   e. wcel 2205   {crab 2526   C_ wss 3214   (/)c0 3512   {csn 3694  EXMIDwem 4312

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-14 2208  ax-ext 2216  ax-sep 4233  ax-nul 4241  ax-pow 4292

This theorem depends on definitions:  df-bi 117  df-dc 843  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-rab 2531  df-v 2817  df-dif 3216  df-in 3220  df-ss 3227  df-nul 3513  df-pw 3676  df-sn 3700  df-exmid 4313

This theorem is referenced by:  exmidn0m  4319  exmid0el  4322  exmidel  4323  exmidundif  4324  exmidundifim  4325  exmidpw2en  7185  exmidssfi  7212  sbthlemi3  7242  sbthlemi5  7244  sbthlemi6  7245  exmidomniim  7445  exmidfodomrlemim  7517  exmidontriimlem1  7541  exmidapne  7590  pw1dceq  16904  exmidnotnotr  16905  exmidcon  16906  exmidpeirce  16907