Description: 2 is not a limit ordinal. (Contributed by BTernaryTau, 1-Dec-2024) (Proof shortened by RP, 13-Dec-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | nlim2NEW | |- -. Lim 2o |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 1on | |- 1o e. On |
|
2 | nlimsuc | |- ( 1o e. On -> -. Lim suc 1o ) |
|
3 | df-2o | |- 2o = suc 1o |
|
4 | limeq | |- ( 2o = suc 1o -> ( Lim 2o <-> Lim suc 1o ) ) |
|
5 | 3 4 | ax-mp | |- ( Lim 2o <-> Lim suc 1o ) |
6 | 2 5 | sylnibr | |- ( 1o e. On -> -. Lim 2o ) |
7 | 1 6 | ax-mp | |- -. Lim 2o |