Description: Define the ordinal number 2. (Contributed by NM, 18-Feb-2004)
Ref | Expression | ||
---|---|---|---|
Assertion | df-2o | |- 2o = suc 1o |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | c2o | |- 2o |
|
1 | c1o | |- 1o |
|
2 | 1 | csuc | |- suc 1o |
3 | 0 2 | wceq | |- 2o = suc 1o |