Description: A natural number is ordinal. (Contributed by NM, 17-Oct-1995)
Ref | Expression | ||
---|---|---|---|
Assertion | nnord | ⊢ ( 𝐴 ∈ ω → Ord 𝐴 ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nnon | ⊢ ( 𝐴 ∈ ω → 𝐴 ∈ On ) | |
2 | eloni | ⊢ ( 𝐴 ∈ On → Ord 𝐴 ) | |
3 | 1 2 | syl | ⊢ ( 𝐴 ∈ ω → Ord 𝐴 ) |