Theorem phplem4 6911

Description: Lemma for Pigeonhole Principle. Equinumerosity of successors implies equinumerosity of the original natural numbers. (Contributed by NM, 28-May-1998.) (Revised by Mario Carneiro, 24-Jun-2015.)

Hypotheses

Ref	Expression
phplem2.1	|- A e. _V
phplem2.2	|- B e. _V

Assertion

Ref	Expression
phplem4	|- ( ( A e. om /\ B e. om ) -> ( suc A ~~ suc B -> A ~~ B ) )

Proof of Theorem phplem4

Dummy variable f is distinct from all other variables.

Step	Hyp	Ref	Expression
1		bren 6801	. 2 |- ( suc A ~~ suc B <-> E. f f : suc A -1-1-onto-> suc B )
2		f1of1 5499	. . . . . . . . . 10 |- ( f : suc A -1-1-onto-> suc B -> f : suc A -1-1-> suc B )
3	2	adantl 277	. . . . . . . . 9 |- ( ( A e. om /\ f : suc A -1-1-onto-> suc B ) -> f : suc A -1-1-> suc B )
4		phplem2.2	. . . . . . . . . 10 |- B e. _V
5	4	sucex 4531	. . . . . . . . 9 |- suc B e. _V
6		sssucid 4446	. . . . . . . . . 10 |- A C_ suc A
7		phplem2.1	. . . . . . . . . 10 |- A e. _V
8		f1imaen2g 6847	. . . . . . . . . 10 |- ( ( ( f : suc A -1-1-> suc B /\ suc B e. _V ) /\ ( A C_ suc A /\ A e. _V ) ) -> ( f " A ) ~~ A )
9	6, 7, 8	mpanr12 439	. . . . . . . . 9 |- ( ( f : suc A -1-1-> suc B /\ suc B e. _V ) -> ( f " A ) ~~ A )
10	3, 5, 9	sylancl 413	. . . . . . . 8 |- ( ( A e. om /\ f : suc A -1-1-onto-> suc B ) -> ( f " A ) ~~ A )
11	10	ensymd 6837	. . . . . . 7 |- ( ( A e. om /\ f : suc A -1-1-onto-> suc B ) -> A ~~ ( f " A ) )
12		nnord 4644	. . . . . . . . . 10 |- ( A e. om -> Ord A )
13		orddif 4579	. . . . . . . . . 10 |- ( Ord A -> A = ( suc A \ { A } ) )
14	12, 13	syl 14	. . . . . . . . 9 |- ( A e. om -> A = ( suc A \ { A } ) )
15	14	imaeq2d 5005	. . . . . . . 8 |- ( A e. om -> ( f " A ) = ( f " ( suc A \ { A } ) ) )
16		f1ofn 5501	. . . . . . . . . . 11 |- ( f : suc A -1-1-onto-> suc B -> f Fn suc A )
17	7	sucid 4448	. . . . . . . . . . 11 |- A e. suc A
18		fnsnfv 5616	. . . . . . . . . . 11 |- ( ( f Fn suc A /\ A e. suc A ) -> { ( f ` A ) } = ( f " { A } ) )
19	16, 17, 18	sylancl 413	. . . . . . . . . 10 |- ( f : suc A -1-1-onto-> suc B -> { ( f ` A ) } = ( f " { A } ) )
20	19	difeq2d 3277	. . . . . . . . 9 |- ( f : suc A -1-1-onto-> suc B -> ( ( f " suc A ) \ { ( f ` A ) } ) = ( ( f " suc A ) \ ( f " { A } ) ) )
21		imadmrn 5015	. . . . . . . . . . . 12 |- ( f " dom f ) = ran f
22	21	eqcomi 2197	. . . . . . . . . . 11 |- ran f = ( f " dom f )
23		f1ofo 5507	. . . . . . . . . . . 12 |- ( f : suc A -1-1-onto-> suc B -> f : suc A -onto-> suc B )
24		forn 5479	. . . . . . . . . . . 12 |- ( f : suc A -onto-> suc B -> ran f = suc B )
25	23, 24	syl 14	. . . . . . . . . . 11 |- ( f : suc A -1-1-onto-> suc B -> ran f = suc B )
26		f1odm 5504	. . . . . . . . . . . 12 |- ( f : suc A -1-1-onto-> suc B -> dom f = suc A )
27	26	imaeq2d 5005	. . . . . . . . . . 11 |- ( f : suc A -1-1-onto-> suc B -> ( f " dom f ) = ( f " suc A ) )
28	22, 25, 27	3eqtr3a 2250	. . . . . . . . . 10 |- ( f : suc A -1-1-onto-> suc B -> suc B = ( f " suc A ) )
29	28	difeq1d 3276	. . . . . . . . 9 |- ( f : suc A -1-1-onto-> suc B -> ( suc B \ { ( f ` A ) } ) = ( ( f " suc A ) \ { ( f ` A ) } ) )
30		dff1o3 5506	. . . . . . . . . . 11 |- ( f : suc A -1-1-onto-> suc B <-> ( f : suc A -onto-> suc B /\ Fun `' f ) )
31	30	simprbi 275	. . . . . . . . . 10 |- ( f : suc A -1-1-onto-> suc B -> Fun `' f )
32		imadif 5334	. . . . . . . . . 10 |- ( Fun `' f -> ( f " ( suc A \ { A } ) ) = ( ( f " suc A ) \ ( f " { A } ) ) )
33	31, 32	syl 14	. . . . . . . . 9 |- ( f : suc A -1-1-onto-> suc B -> ( f " ( suc A \ { A } ) ) = ( ( f " suc A ) \ ( f " { A } ) ) )
34	20, 29, 33	3eqtr4rd 2237	. . . . . . . 8 |- ( f : suc A -1-1-onto-> suc B -> ( f " ( suc A \ { A } ) ) = ( suc B \ { ( f ` A ) } ) )
35	15, 34	sylan9eq 2246	. . . . . . 7 |- ( ( A e. om /\ f : suc A -1-1-onto-> suc B ) -> ( f " A ) = ( suc B \ { ( f ` A ) } ) )
36	11, 35	breqtrd 4055	. . . . . 6 |- ( ( A e. om /\ f : suc A -1-1-onto-> suc B ) -> A ~~ ( suc B \ { ( f ` A ) } ) )
37		fnfvelrn 5690	. . . . . . . . . 10 |- ( ( f Fn suc A /\ A e. suc A ) -> ( f ` A ) e. ran f )
38	16, 17, 37	sylancl 413	. . . . . . . . 9 |- ( f : suc A -1-1-onto-> suc B -> ( f ` A ) e. ran f )
39	24	eleq2d 2263	. . . . . . . . . 10 |- ( f : suc A -onto-> suc B -> ( ( f ` A ) e. ran f <-> ( f ` A ) e. suc B ) )
40	23, 39	syl 14	. . . . . . . . 9 |- ( f : suc A -1-1-onto-> suc B -> ( ( f ` A ) e. ran f <-> ( f ` A ) e. suc B ) )
41	38, 40	mpbid 147	. . . . . . . 8 |- ( f : suc A -1-1-onto-> suc B -> ( f ` A ) e. suc B )
42		vex 2763	. . . . . . . . . 10 |- f e. _V
43	42, 7	fvex 5574	. . . . . . . . 9 |- ( f ` A ) e. _V
44	4, 43	phplem3 6910	. . . . . . . 8 |- ( ( B e. om /\ ( f ` A ) e. suc B ) -> B ~~ ( suc B \ { ( f ` A ) } ) )
45	41, 44	sylan2 286	. . . . . . 7 |- ( ( B e. om /\ f : suc A -1-1-onto-> suc B ) -> B ~~ ( suc B \ { ( f ` A ) } ) )
46	45	ensymd 6837	. . . . . 6 |- ( ( B e. om /\ f : suc A -1-1-onto-> suc B ) -> ( suc B \ { ( f ` A ) } ) ~~ B )
47		entr 6838	. . . . . 6 |- ( ( A ~~ ( suc B \ { ( f ` A ) } ) /\ ( suc B \ { ( f ` A ) } ) ~~ B ) -> A ~~ B )
48	36, 46, 47	syl2an 289	. . . . 5 |- ( ( ( A e. om /\ f : suc A -1-1-onto-> suc B ) /\ ( B e. om /\ f : suc A -1-1-onto-> suc B ) ) -> A ~~ B )
49	48	anandirs 593	. . . 4 |- ( ( ( A e. om /\ B e. om ) /\ f : suc A -1-1-onto-> suc B ) -> A ~~ B )
50	49	ex 115	. . 3 |- ( ( A e. om /\ B e. om ) -> ( f : suc A -1-1-onto-> suc B -> A ~~ B ) )
51	50	exlimdv 1830	. 2 |- ( ( A e. om /\ B e. om ) -> ( E. f f : suc A -1-1-onto-> suc B -> A ~~ B ) )
52	1, 51	biimtrid 152	1 |- ( ( A e. om /\ B e. om ) -> ( suc A ~~ suc B -> A ~~ B ) )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   = wceq 1364   E.wex 1503   e. wcel 2164   _Vcvv 2760   \ cdif 3150   C_ wss 3153   {csn 3618   class class class wbr 4029   Ord word 4393   suc csuc 4396   omcom 4622   `'ccnv 4658   dom cdm 4659   ran crn 4660   "cima 4662   Fun wfun 5248   Fn wfn 5249   -1-1->wf1 5251   -onto->wfo 5252   -1-1-onto->wf1o 5253   ` cfv 5254   ~~ cen 6792

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 615  ax-in2 616  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-13 2166  ax-14 2167  ax-ext 2175  ax-sep 4147  ax-nul 4155  ax-pow 4203  ax-pr 4238  ax-un 4464  ax-setind 4569  ax-iinf 4620

This theorem depends on definitions:  df-bi 117  df-dc 836  df-3or 981  df-3an 982  df-tru 1367  df-fal 1370  df-nf 1472  df-sb 1774  df-eu 2045  df-mo 2046  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-ne 2365  df-ral 2477  df-rex 2478  df-rab 2481  df-v 2762  df-sbc 2986  df-dif 3155  df-un 3157  df-in 3159  df-ss 3166  df-nul 3447  df-pw 3603  df-sn 3624  df-pr 3625  df-op 3627  df-uni 3836  df-int 3871  df-br 4030  df-opab 4091  df-tr 4128  df-id 4324  df-iord 4397  df-on 4399  df-suc 4402  df-iom 4623  df-xp 4665  df-rel 4666  df-cnv 4667  df-co 4668  df-dm 4669  df-rn 4670  df-res 4671  df-ima 4672  df-iota 5215  df-fun 5256  df-fn 5257  df-f 5258  df-f1 5259  df-fo 5260  df-f1o 5261  df-fv 5262  df-er 6587  df-en 6795

This theorem is referenced by:  nneneq  6913  php5  6914