Theorem nntri3or 6726

Description: Trichotomy for natural numbers. (Contributed by Jim Kingdon, 25-Aug-2019.)

Assertion

Ref	Expression
nntri3or	|- ( ( A e. om /\ B e. om ) -> ( A e. B \/ A = B \/ B e. A ) )

Proof of Theorem nntri3or

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

Step	Hyp	Ref	Expression
1		eleq2 2296	. . . . 5 |- ( x = B -> ( A e. x <-> A e. B ) )
2		eqeq2 2242	. . . . 5 |- ( x = B -> ( A = x <-> A = B ) )
3		eleq1 2295	. . . . 5 |- ( x = B -> ( x e. A <-> B e. A ) )
4	1, 2, 3	3orbi123d 1348	. . . 4 |- ( x = B -> ( ( A e. x \/ A = x \/ x e. A ) <-> ( A e. B \/ A = B \/ B e. A ) ) )
5	4	imbi2d 230	. . 3 |- ( x = B -> ( ( A e. om -> ( A e. x \/ A = x \/ x e. A ) ) <-> ( A e. om -> ( A e. B \/ A = B \/ B e. A ) ) ) )
6		eleq2 2296	. . . . 5 |- ( x = (/) -> ( A e. x <-> A e. (/) ) )
7		eqeq2 2242	. . . . 5 |- ( x = (/) -> ( A = x <-> A = (/) ) )
8		eleq1 2295	. . . . 5 |- ( x = (/) -> ( x e. A <-> (/) e. A ) )
9	6, 7, 8	3orbi123d 1348	. . . 4 |- ( x = (/) -> ( ( A e. x \/ A = x \/ x e. A ) <-> ( A e. (/) \/ A = (/) \/ (/) e. A ) ) )
10		eleq2 2296	. . . . 5 |- ( x = y -> ( A e. x <-> A e. y ) )
11		eqeq2 2242	. . . . 5 |- ( x = y -> ( A = x <-> A = y ) )
12		eleq1 2295	. . . . 5 |- ( x = y -> ( x e. A <-> y e. A ) )
13	10, 11, 12	3orbi123d 1348	. . . 4 |- ( x = y -> ( ( A e. x \/ A = x \/ x e. A ) <-> ( A e. y \/ A = y \/ y e. A ) ) )
14		eleq2 2296	. . . . 5 |- ( x = suc y -> ( A e. x <-> A e. suc y ) )
15		eqeq2 2242	. . . . 5 |- ( x = suc y -> ( A = x <-> A = suc y ) )
16		eleq1 2295	. . . . 5 |- ( x = suc y -> ( x e. A <-> suc y e. A ) )
17	14, 15, 16	3orbi123d 1348	. . . 4 |- ( x = suc y -> ( ( A e. x \/ A = x \/ x e. A ) <-> ( A e. suc y \/ A = suc y \/ suc y e. A ) ) )
18		0elnn 4741	. . . . 5 |- ( A e. om -> ( A = (/) \/ (/) e. A ) )
19		olc 719	. . . . . 6 |- ( ( A = (/) \/ (/) e. A ) -> ( A e. (/) \/ ( A = (/) \/ (/) e. A ) ) )
20		3orass 1008	. . . . . 6 |- ( ( A e. (/) \/ A = (/) \/ (/) e. A ) <-> ( A e. (/) \/ ( A = (/) \/ (/) e. A ) ) )
21	19, 20	sylibr 134	. . . . 5 |- ( ( A = (/) \/ (/) e. A ) -> ( A e. (/) \/ A = (/) \/ (/) e. A ) )
22	18, 21	syl 14	. . . 4 |- ( A e. om -> ( A e. (/) \/ A = (/) \/ (/) e. A ) )
23		df-3or 1006	. . . . . 6 |- ( ( A e. y \/ A = y \/ y e. A ) <-> ( ( A e. y \/ A = y ) \/ y e. A ) )
24		elex 2825	. . . . . . . 8 |- ( y e. om -> y e. _V )
25		elsuc2g 4526	. . . . . . . . 9 |- ( y e. _V -> ( A e. suc y <-> ( A e. y \/ A = y ) ) )
26		3mix1 1193	. . . . . . . . 9 |- ( A e. suc y -> ( A e. suc y \/ A = suc y \/ suc y e. A ) )
27	25, 26	biimtrrdi 164	. . . . . . . 8 |- ( y e. _V -> ( ( A e. y \/ A = y ) -> ( A e. suc y \/ A = suc y \/ suc y e. A ) ) )
28	24, 27	syl 14	. . . . . . 7 |- ( y e. om -> ( ( A e. y \/ A = y ) -> ( A e. suc y \/ A = suc y \/ suc y e. A ) ) )
29		nnsucelsuc 6724	. . . . . . . . 9 |- ( A e. om -> ( y e. A <-> suc y e. suc A ) )
30		elsuci 4524	. . . . . . . . 9 |- ( suc y e. suc A -> ( suc y e. A \/ suc y = A ) )
31	29, 30	biimtrdi 163	. . . . . . . 8 |- ( A e. om -> ( y e. A -> ( suc y e. A \/ suc y = A ) ) )
32		eqcom 2234	. . . . . . . . . . . . 13 |- ( suc y = A <-> A = suc y )
33	32	orbi2i 770	. . . . . . . . . . . 12 |- ( ( suc y e. A \/ suc y = A ) <-> ( suc y e. A \/ A = suc y ) )
34	33	biimpi 120	. . . . . . . . . . 11 |- ( ( suc y e. A \/ suc y = A ) -> ( suc y e. A \/ A = suc y ) )
35	34	orcomd 737	. . . . . . . . . 10 |- ( ( suc y e. A \/ suc y = A ) -> ( A = suc y \/ suc y e. A ) )
36	35	olcd 742	. . . . . . . . 9 |- ( ( suc y e. A \/ suc y = A ) -> ( A e. suc y \/ ( A = suc y \/ suc y e. A ) ) )
37		3orass 1008	. . . . . . . . 9 |- ( ( A e. suc y \/ A = suc y \/ suc y e. A ) <-> ( A e. suc y \/ ( A = suc y \/ suc y e. A ) ) )
38	36, 37	sylibr 134	. . . . . . . 8 |- ( ( suc y e. A \/ suc y = A ) -> ( A e. suc y \/ A = suc y \/ suc y e. A ) )
39	31, 38	syl6 33	. . . . . . 7 |- ( A e. om -> ( y e. A -> ( A e. suc y \/ A = suc y \/ suc y e. A ) ) )
40	28, 39	jaao 727	. . . . . 6 |- ( ( y e. om /\ A e. om ) -> ( ( ( A e. y \/ A = y ) \/ y e. A ) -> ( A e. suc y \/ A = suc y \/ suc y e. A ) ) )
41	23, 40	biimtrid 152	. . . . 5 |- ( ( y e. om /\ A e. om ) -> ( ( A e. y \/ A = y \/ y e. A ) -> ( A e. suc y \/ A = suc y \/ suc y e. A ) ) )
42	41	ex 115	. . . 4 |- ( y e. om -> ( A e. om -> ( ( A e. y \/ A = y \/ y e. A ) -> ( A e. suc y \/ A = suc y \/ suc y e. A ) ) ) )
43	9, 13, 17, 22, 42	finds2 4723	. . 3 |- ( x e. om -> ( A e. om -> ( A e. x \/ A = x \/ x e. A ) ) )
44	5, 43	vtoclga 2881	. 2 |- ( B e. om -> ( A e. om -> ( A e. B \/ A = B \/ B e. A ) ) )
45	44	impcom 125	1 |- ( ( A e. om /\ B e. om ) -> ( A e. B \/ A = B \/ B e. A ) )

Syntax hints:   -> wi 4   /\ wa 104   \/ wo 716   \/ w3o 1004   = wceq 1398   e. wcel 2203   _Vcvv 2813   (/)c0 3508   suc csuc 4486   omcom 4712

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 2205  ax-14 2206  ax-ext 2214  ax-sep 4228  ax-nul 4236  ax-pow 4287  ax-pr 4322  ax-un 4554  ax-iinf 4710

This theorem depends on definitions:  df-bi 117  df-3or 1006  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-ral 2525  df-rex 2526  df-v 2815  df-dif 3213  df-un 3215  df-in 3217  df-ss 3224  df-nul 3509  df-pw 3671  df-sn 3695  df-pr 3696  df-uni 3915  df-int 3950  df-tr 4209  df-iord 4487  df-on 4489  df-suc 4492  df-iom 4713

This theorem is referenced by:  nntri2  6727  nntri1  6729  nntri3  6730  nntri2or2  6731  nndceq  6732  nndcel  6733  nnsseleq  6734  nntr2  6736  nnawordex  6762  nnwetri  7176  nnnninfeq  7419  ltsopi  7635  pitri3or  7637  frec2uzlt2d  10766  nninfctlemfo  12736  ennnfonelemk  13151  ennnfonelemex  13165