Theorem nn1suc 8897

Description: If a statement holds for 1 and also holds for a successor, it holds for all positive integers. The first three hypotheses give us the substitution instances we need; the last two show that it holds for 1 and for a successor. (Contributed by NM, 11-Oct-2004.) (Revised by Mario Carneiro, 16-May-2014.)

Hypotheses

Ref	Expression
nn1suc.1	|- ( x = 1 -> ( ph <-> ps ) )
nn1suc.3	|- ( x = ( y + 1 ) -> ( ph <-> ch ) )
nn1suc.4	|- ( x = A -> ( ph <-> th ) )
nn1suc.5	|- ps
nn1suc.6	|- ( y e. NN -> ch )

Assertion

Ref	Expression
nn1suc	|- ( A e. NN -> th )

Distinct variable groups:   x, y, A   ps, x   ch, x   th, x   ph, y

Allowed substitution hints:   ph( x)   ps( y)   ch( y)   th( y)

Proof of Theorem nn1suc

Step	Hyp	Ref	Expression
1		nn1suc.5	. . . . 5 |- ps
2		1ex 7915	. . . . . 6 |- 1 e. _V
3		nn1suc.1	. . . . . 6 |- ( x = 1 -> ( ph <-> ps ) )
4	2, 3	sbcie 2989	. . . . 5 |- ( [. 1 / x ]. ph <-> ps )
5	1, 4	mpbir 145	. . . 4 |- [. 1 / x ]. ph
6		1nn 8889	. . . . . . 7 |- 1 e. NN
7		eleq1 2233	. . . . . . 7 |- ( A = 1 -> ( A e. NN <-> 1 e. NN ) )
8	6, 7	mpbiri 167	. . . . . 6 |- ( A = 1 -> A e. NN )
9		nn1suc.4	. . . . . . 7 |- ( x = A -> ( ph <-> th ) )
10	9	sbcieg 2987	. . . . . 6 |- ( A e. NN -> ( [. A / x ]. ph <-> th ) )
11	8, 10	syl 14	. . . . 5 |- ( A = 1 -> ( [. A / x ]. ph <-> th ) )
12		dfsbcq 2957	. . . . 5 |- ( A = 1 -> ( [. A / x ]. ph <-> [. 1 / x ]. ph ) )
13	11, 12	bitr3d 189	. . . 4 |- ( A = 1 -> ( th <-> [. 1 / x ]. ph ) )
14	5, 13	mpbiri 167	. . 3 |- ( A = 1 -> th )
15	14	a1i 9	. 2 |- ( A e. NN -> ( A = 1 -> th ) )
16		elisset 2744	. . . 4 |- ( ( A - 1 ) e. NN -> E. y y = ( A - 1 ) )
17		eleq1 2233	. . . . . 6 |- ( y = ( A - 1 ) -> ( y e. NN <-> ( A - 1 ) e. NN ) )
18	17	pm5.32ri 452	. . . . 5 |- ( ( y e. NN /\ y = ( A - 1 ) ) <-> ( ( A - 1 ) e. NN /\ y = ( A - 1 ) ) )
19		nn1suc.6	. . . . . . 7 |- ( y e. NN -> ch )
20	19	adantr 274	. . . . . 6 |- ( ( y e. NN /\ y = ( A - 1 ) ) -> ch )
21		nnre 8885	. . . . . . . . 9 |- ( y e. NN -> y e. RR )
22		peano2re 8055	. . . . . . . . 9 |- ( y e. RR -> ( y + 1 ) e. RR )
23		nn1suc.3	. . . . . . . . . 10 |- ( x = ( y + 1 ) -> ( ph <-> ch ) )
24	23	sbcieg 2987	. . . . . . . . 9 |- ( ( y + 1 ) e. RR -> ( [. ( y + 1 ) / x ]. ph <-> ch ) )
25	21, 22, 24	3syl 17	. . . . . . . 8 |- ( y e. NN -> ( [. ( y + 1 ) / x ]. ph <-> ch ) )
26	25	adantr 274	. . . . . . 7 |- ( ( y e. NN /\ y = ( A - 1 ) ) -> ( [. ( y + 1 ) / x ]. ph <-> ch ) )
27		oveq1 5860	. . . . . . . . 9 |- ( y = ( A - 1 ) -> ( y + 1 ) = ( ( A - 1 ) + 1 ) )
28	27	sbceq1d 2960	. . . . . . . 8 |- ( y = ( A - 1 ) -> ( [. ( y + 1 ) / x ]. ph <-> [. ( ( A - 1 ) + 1 ) / x ]. ph ) )
29	28	adantl 275	. . . . . . 7 |- ( ( y e. NN /\ y = ( A - 1 ) ) -> ( [. ( y + 1 ) / x ]. ph <-> [. ( ( A - 1 ) + 1 ) / x ]. ph ) )
30	26, 29	bitr3d 189	. . . . . 6 |- ( ( y e. NN /\ y = ( A - 1 ) ) -> ( ch <-> [. ( ( A - 1 ) + 1 ) / x ]. ph ) )
31	20, 30	mpbid 146	. . . . 5 |- ( ( y e. NN /\ y = ( A - 1 ) ) -> [. ( ( A - 1 ) + 1 ) / x ]. ph )
32	18, 31	sylbir 134	. . . 4 |- ( ( ( A - 1 ) e. NN /\ y = ( A - 1 ) ) -> [. ( ( A - 1 ) + 1 ) / x ]. ph )
33	16, 32	exlimddv 1891	. . 3 |- ( ( A - 1 ) e. NN -> [. ( ( A - 1 ) + 1 ) / x ]. ph )
34		nncn 8886	. . . . . 6 |- ( A e. NN -> A e. CC )
35		ax-1cn 7867	. . . . . 6 |- 1 e. CC
36		npcan 8128	. . . . . 6 |- ( ( A e. CC /\ 1 e. CC ) -> ( ( A - 1 ) + 1 ) = A )
37	34, 35, 36	sylancl 411	. . . . 5 |- ( A e. NN -> ( ( A - 1 ) + 1 ) = A )
38	37	sbceq1d 2960	. . . 4 |- ( A e. NN -> ( [. ( ( A - 1 ) + 1 ) / x ]. ph <-> [. A / x ]. ph ) )
39	38, 10	bitrd 187	. . 3 |- ( A e. NN -> ( [. ( ( A - 1 ) + 1 ) / x ]. ph <-> th ) )
40	33, 39	syl5ib 153	. 2 |- ( A e. NN -> ( ( A - 1 ) e. NN -> th ) )
41		nn1m1nn 8896	. 2 |- ( A e. NN -> ( A = 1 \/ ( A - 1 ) e. NN ) )
42	15, 40, 41	mpjaod 713	1 |- ( A e. NN -> th )

Syntax hints:   -> wi 4   /\ wa 103   <-> wb 104   = wceq 1348   e. wcel 2141   [.wsbc 2955  (class class class)co 5853   CCcc 7772   RRcr 7773   1c1 7775   + caddc 7777   - cmin 8090   NNcn 8878

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 609  ax-in2 610  ax-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-14 2144  ax-ext 2152  ax-sep 4107  ax-pow 4160  ax-pr 4194  ax-setind 4521  ax-cnex 7865  ax-resscn 7866  ax-1cn 7867  ax-1re 7868  ax-icn 7869  ax-addcl 7870  ax-addrcl 7871  ax-mulcl 7872  ax-addcom 7874  ax-addass 7876  ax-distr 7878  ax-i2m1 7879  ax-0id 7882  ax-rnegex 7883  ax-cnre 7885

This theorem depends on definitions:  df-bi 116  df-3an 975  df-tru 1351  df-fal 1354  df-nf 1454  df-sb 1756  df-eu 2022  df-mo 2023  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-ne 2341  df-ral 2453  df-rex 2454  df-reu 2455  df-rab 2457  df-v 2732  df-sbc 2956  df-dif 3123  df-un 3125  df-in 3127  df-ss 3134  df-pw 3568  df-sn 3589  df-pr 3590  df-op 3592  df-uni 3797  df-int 3832  df-br 3990  df-opab 4051  df-id 4278  df-xp 4617  df-rel 4618  df-cnv 4619  df-co 4620  df-dm 4621  df-iota 5160  df-fun 5200  df-fv 5206  df-riota 5809  df-ov 5856  df-oprab 5857  df-mpo 5858  df-sub 8092  df-inn 8879

This theorem is referenced by: (None)