Description: A finite set of sequential integer is countable. (Contributed by Glauco Siliprandi, 8-Apr-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | fzct | ⊢ ( 𝑁 ... 𝑀 ) ≼ ω |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fzssz | ⊢ ( 𝑁 ... 𝑀 ) ⊆ ℤ | |
2 | zct | ⊢ ℤ ≼ ω | |
3 | ssct | ⊢ ( ( ( 𝑁 ... 𝑀 ) ⊆ ℤ ∧ ℤ ≼ ω ) → ( 𝑁 ... 𝑀 ) ≼ ω ) | |
4 | 1 2 3 | mp2an | ⊢ ( 𝑁 ... 𝑀 ) ≼ ω |