Metamath Proof Explorer


Theorem nndiffz1

Description: Upper set of the positive integers. (Contributed by Thierry Arnoux, 22-Aug-2017)

Ref Expression
Assertion nndiffz1 N01N=N+1

Proof

Step Hyp Ref Expression
1 1z 1
2 nn0z N0N
3 elfz1 1Nj1Nj1jjN
4 1 2 3 sylancr N0j1Nj1jjN
5 3anass j1jjNj1jjN
6 4 5 bitrdi N0j1Nj1jjN
7 6 baibd N0jj1N1jjN
8 7 baibd N0j1jj1NjN
9 8 notbid N0j1j¬j1N¬jN
10 simpl NjN
11 10 zred NjN
12 simpr Njj
13 12 zred Njj
14 11 13 ltnled NjN<j¬jN
15 zltp1le NjN<jN+1j
16 14 15 bitr3d Nj¬jNN+1j
17 2 16 sylan N0j¬jNN+1j
18 17 adantr N0j1j¬jNN+1j
19 9 18 bitrd N0j1j¬j1NN+1j
20 19 pm5.32da N0j1j¬j1N1jN+1j
21 1red N0jN+1j1
22 simpll N0jN+1jN0
23 22 nn0red N0jN+1jN
24 23 21 readdcld N0jN+1jN+1
25 simplr N0jN+1jj
26 25 zred N0jN+1jj
27 0p1e1 0+1=1
28 0red N0jN+1j0
29 22 nn0ge0d N0jN+1j0N
30 28 23 21 29 leadd1dd N0jN+1j0+1N+1
31 27 30 eqbrtrrid N0jN+1j1N+1
32 simpr N0jN+1jN+1j
33 21 24 26 31 32 letrd N0jN+1j1j
34 33 ex N0jN+1j1j
35 34 pm4.71rd N0jN+1j1jN+1j
36 20 35 bitr4d N0j1j¬j1NN+1j
37 36 pm5.32da N0j1j¬j1NjN+1j
38 eldif j1Nj¬j1N
39 elnnz1 jj1j
40 39 anbi1i j¬j1Nj1j¬j1N
41 anass j1j¬j1Nj1j¬j1N
42 38 40 41 3bitri j1Nj1j¬j1N
43 42 a1i N0j1Nj1j¬j1N
44 peano2nn0 N0N+10
45 44 nn0zd N0N+1
46 eluz1 N+1jN+1jN+1j
47 45 46 syl N0jN+1jN+1j
48 37 43 47 3bitr4d N0j1NjN+1
49 48 eqrdv N01N=N+1