Description: 9 + 8 = 17. (Contributed by Mario Carneiro, 19-Apr-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | 9p8e17 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 9nn0 | |
|
2 | 7nn0 | |
|
3 | 6nn0 | |
|
4 | df-8 | |
|
5 | df-7 | |
|
6 | 9p7e16 | |
|
7 | 1 2 3 4 5 6 | 6p5lem | |