Description: Define the number 4. (Contributed by NM, 27-May-1999)
Ref | Expression | ||
---|---|---|---|
Assertion | df-4 | |- 4 = ( 3 + 1 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | c4 | |- 4 |
|
1 | c3 | |- 3 |
|
2 | caddc | |- + |
|
3 | c1 | |- 1 |
|
4 | 1 3 2 | co | |- ( 3 + 1 ) |
5 | 0 4 | wceq | |- 4 = ( 3 + 1 ) |