Description: Ordering property of multiplication. Proposition 8.19 of TakeutiZaring p. 63, limited to natural numbers. (Contributed by NM, 22-Jan-1996) (Revised by Mario Carneiro, 15-Nov-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | nnmord | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nnmordi | |
|
2 | 1 | ex | |
3 | 2 | impcomd | |
4 | 3 | 3adant1 | |
5 | ne0i | |
|
6 | nnm0r | |
|
7 | oveq1 | |
|
8 | 7 | eqeq1d | |
9 | 6 8 | syl5ibrcom | |
10 | 9 | necon3d | |
11 | 5 10 | syl5 | |
12 | 11 | adantr | |
13 | nnord | |
|
14 | ord0eln0 | |
|
15 | 13 14 | syl | |
16 | 15 | adantl | |
17 | 12 16 | sylibrd | |
18 | 17 | 3adant1 | |
19 | oveq2 | |
|
20 | 19 | a1i | |
21 | nnmordi | |
|
22 | 21 | 3adantl2 | |
23 | 20 22 | orim12d | |
24 | 23 | con3d | |
25 | simpl3 | |
|
26 | simpl1 | |
|
27 | nnmcl | |
|
28 | 25 26 27 | syl2anc | |
29 | simpl2 | |
|
30 | nnmcl | |
|
31 | 25 29 30 | syl2anc | |
32 | nnord | |
|
33 | nnord | |
|
34 | ordtri2 | |
|
35 | 32 33 34 | syl2an | |
36 | 28 31 35 | syl2anc | |
37 | nnord | |
|
38 | nnord | |
|
39 | ordtri2 | |
|
40 | 37 38 39 | syl2an | |
41 | 26 29 40 | syl2anc | |
42 | 24 36 41 | 3imtr4d | |
43 | 42 | ex | |
44 | 43 | com23 | |
45 | 18 44 | mpdd | |
46 | 45 18 | jcad | |
47 | 4 46 | impbid | |