Description: Define the number 7. (Contributed by NM, 27-May-1999)
Ref | Expression | ||
---|---|---|---|
Assertion | df-7 | |- 7 = ( 6 + 1 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | c7 | |- 7 |
|
1 | c6 | |- 6 |
|
2 | caddc | |- + |
|
3 | c1 | |- 1 |
|
4 | 1 3 2 | co | |- ( 6 + 1 ) |
5 | 0 4 | wceq | |- 7 = ( 6 + 1 ) |