Description: The restriction of a finite set is finite. (Contributed by Alexander van der Vekens, 3-Jan-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | finresfin | ⊢ ( 𝐸 ∈ Fin → ( 𝐸 ↾ 𝐵 ) ∈ Fin ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | resss | ⊢ ( 𝐸 ↾ 𝐵 ) ⊆ 𝐸 | |
| 2 | ssfi | ⊢ ( ( 𝐸 ∈ Fin ∧ ( 𝐸 ↾ 𝐵 ) ⊆ 𝐸 ) → ( 𝐸 ↾ 𝐵 ) ∈ Fin ) | |
| 3 | 1 2 | mpan2 | ⊢ ( 𝐸 ∈ Fin → ( 𝐸 ↾ 𝐵 ) ∈ Fin ) |