Description: 3 is not a limit ordinal. (Contributed by RP, 13-Dec-2024)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nlim3 | |- -. Lim 3o |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 2on | |- 2o e. On |
|
| 2 | nlimsuc | |- ( 2o e. On -> -. Lim suc 2o ) |
|
| 3 | df-3o | |- 3o = suc 2o |
|
| 4 | limeq | |- ( 3o = suc 2o -> ( Lim 3o <-> Lim suc 2o ) ) |
|
| 5 | 3 4 | ax-mp | |- ( Lim 3o <-> Lim suc 2o ) |
| 6 | 2 5 | sylnibr | |- ( 2o e. On -> -. Lim 3o ) |
| 7 | 1 6 | ax-mp | |- -. Lim 3o |