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 ∈ On | |
2 | nlimsuc | ⊢ ( 2o ∈ 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 ∈ On → ¬ Lim 3o ) |
7 | 1 6 | ax-mp | ⊢ ¬ Lim 3o |