Description: Ordering property of addition for positive integers. (Contributed by NM, 7-Mar-1996) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | ltapi | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dmaddpi | |
|
2 | ltrelpi | |
|
3 | 0npi | |
|
4 | pinn | |
|
5 | pinn | |
|
6 | pinn | |
|
7 | nnaord | |
|
8 | 4 5 6 7 | syl3an | |
9 | 8 | 3expa | |
10 | ltpiord | |
|
11 | 10 | adantr | |
12 | addclpi | |
|
13 | addclpi | |
|
14 | ltpiord | |
|
15 | 12 13 14 | syl2an | |
16 | addpiord | |
|
17 | 16 | adantr | |
18 | addpiord | |
|
19 | 18 | adantl | |
20 | 17 19 | eleq12d | |
21 | 15 20 | bitrd | |
22 | 21 | anandis | |
23 | 22 | ancoms | |
24 | 9 11 23 | 3bitr4d | |
25 | 24 | 3impa | |
26 | 1 2 3 25 | ndmovord | |