Theorem nnawordex 6692

Description: Equivalence for weak ordering of natural numbers. (Contributed by NM, 8-Nov-2002.) (Revised by Mario Carneiro, 15-Nov-2014.)

Assertion

Ref	Expression
nnawordex	|- ( ( A e. om /\ B e. om ) -> ( A C_ B <-> E. x e. om ( A +o x ) = B ) )

Distinct variable groups:   x, A   x, B

Proof of Theorem nnawordex

Step	Hyp	Ref	Expression
1		nntri3or 6656	. . . . 5 |- ( ( A e. om /\ B e. om ) -> ( A e. B \/ A = B \/ B e. A ) )
2	1	3adant3 1041	. . . 4 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> ( A e. B \/ A = B \/ B e. A ) )
3		nnaordex 6691	. . . . . . 7 |- ( ( A e. om /\ B e. om ) -> ( A e. B <-> E. x e. om ( (/) e. x /\ ( A +o x ) = B ) ) )
4		simpr 110	. . . . . . . 8 |- ( ( (/) e. x /\ ( A +o x ) = B ) -> ( A +o x ) = B )
5	4	reximi 2627	. . . . . . 7 |- ( E. x e. om ( (/) e. x /\ ( A +o x ) = B ) -> E. x e. om ( A +o x ) = B )
6	3, 5	biimtrdi 163	. . . . . 6 |- ( ( A e. om /\ B e. om ) -> ( A e. B -> E. x e. om ( A +o x ) = B ) )
7	6	3adant3 1041	. . . . 5 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> ( A e. B -> E. x e. om ( A +o x ) = B ) )
8		nna0 6637	. . . . . . . 8 |- ( A e. om -> ( A +o (/) ) = A )
9	8	3ad2ant1 1042	. . . . . . 7 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> ( A +o (/) ) = A )
10		eqeq2 2239	. . . . . . 7 |- ( A = B -> ( ( A +o (/) ) = A <-> ( A +o (/) ) = B ) )
11	9, 10	syl5ibcom 155	. . . . . 6 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> ( A = B -> ( A +o (/) ) = B ) )
12		peano1 4690	. . . . . . 7 |- (/) e. om
13		oveq2 6021	. . . . . . . . 9 |- ( x = (/) -> ( A +o x ) = ( A +o (/) ) )
14	13	eqeq1d 2238	. . . . . . . 8 |- ( x = (/) -> ( ( A +o x ) = B <-> ( A +o (/) ) = B ) )
15	14	rspcev 2908	. . . . . . 7 |- ( ( (/) e. om /\ ( A +o (/) ) = B ) -> E. x e. om ( A +o x ) = B )
16	12, 15	mpan 424	. . . . . 6 |- ( ( A +o (/) ) = B -> E. x e. om ( A +o x ) = B )
17	11, 16	syl6 33	. . . . 5 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> ( A = B -> E. x e. om ( A +o x ) = B ) )
18		nntri1 6659	. . . . . . 7 |- ( ( A e. om /\ B e. om ) -> ( A C_ B <-> -. B e. A ) )
19	18	biimp3a 1379	. . . . . 6 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> -. B e. A )
20	19	pm2.21d 622	. . . . 5 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> ( B e. A -> E. x e. om ( A +o x ) = B ) )
21	7, 17, 20	3jaod 1338	. . . 4 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> ( ( A e. B \/ A = B \/ B e. A ) -> E. x e. om ( A +o x ) = B ) )
22	2, 21	mpd 13	. . 3 |- ( ( A e. om /\ B e. om /\ A C_ B ) -> E. x e. om ( A +o x ) = B )
23	22	3expia 1229	. 2 |- ( ( A e. om /\ B e. om ) -> ( A C_ B -> E. x e. om ( A +o x ) = B ) )
24		nnaword1 6676	. . . . 5 |- ( ( A e. om /\ x e. om ) -> A C_ ( A +o x ) )
25		sseq2 3249	. . . . 5 |- ( ( A +o x ) = B -> ( A C_ ( A +o x ) <-> A C_ B ) )
26	24, 25	syl5ibcom 155	. . . 4 |- ( ( A e. om /\ x e. om ) -> ( ( A +o x ) = B -> A C_ B ) )
27	26	rexlimdva 2648	. . 3 |- ( A e. om -> ( E. x e. om ( A +o x ) = B -> A C_ B ) )
28	27	adantr 276	. 2 |- ( ( A e. om /\ B e. om ) -> ( E. x e. om ( A +o x ) = B -> A C_ B ) )
29	23, 28	impbid 129	1 |- ( ( A e. om /\ B e. om ) -> ( A C_ B <-> E. x e. om ( A +o x ) = B ) )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   <-> wb 105   \/ w3o 1001   /\ w3a 1002   = wceq 1395   e. wcel 2200   E.wrex 2509   C_ wss 3198   (/)c0 3492   omcom 4686  (class class class)co 6013   +o coa 6574

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 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-13 2202  ax-14 2203  ax-ext 2211  ax-coll 4202  ax-sep 4205  ax-nul 4213  ax-pow 4262  ax-pr 4297  ax-un 4528  ax-setind 4633  ax-iinf 4684

This theorem depends on definitions:  df-bi 117  df-3or 1003  df-3an 1004  df-tru 1398  df-fal 1401  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ne 2401  df-ral 2513  df-rex 2514  df-reu 2515  df-rab 2517  df-v 2802  df-sbc 3030  df-csb 3126  df-dif 3200  df-un 3202  df-in 3204  df-ss 3211  df-nul 3493  df-pw 3652  df-sn 3673  df-pr 3674  df-op 3676  df-uni 3892  df-int 3927  df-iun 3970  df-br 4087  df-opab 4149  df-mpt 4150  df-tr 4186  df-id 4388  df-iord 4461  df-on 4463  df-suc 4466  df-iom 4687  df-xp 4729  df-rel 4730  df-cnv 4731  df-co 4732  df-dm 4733  df-rn 4734  df-res 4735  df-ima 4736  df-iota 5284  df-fun 5326  df-fn 5327  df-f 5328  df-f1 5329  df-fo 5330  df-f1o 5331  df-fv 5332  df-ov 6016  df-oprab 6017  df-mpo 6018  df-1st 6298  df-2nd 6299  df-recs 6466  df-irdg 6531  df-1o 6577  df-oadd 6581

This theorem is referenced by:  prarloclemn  7709