Description: Membership in an upper set of integers. (Contributed by NM, 5-Sep-2005)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | eluz.1 | ⊢ 𝑀 ∈ ℤ | |
| Assertion | eluz1i | ⊢ ( 𝑁 ∈ ( ℤ≥ ‘ 𝑀 ) ↔ ( 𝑁 ∈ ℤ ∧ 𝑀 ≤ 𝑁 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eluz.1 | ⊢ 𝑀 ∈ ℤ | |
| 2 | eluz1 | ⊢ ( 𝑀 ∈ ℤ → ( 𝑁 ∈ ( ℤ≥ ‘ 𝑀 ) ↔ ( 𝑁 ∈ ℤ ∧ 𝑀 ≤ 𝑁 ) ) ) | |
| 3 | 1 2 | ax-mp | ⊢ ( 𝑁 ∈ ( ℤ≥ ‘ 𝑀 ) ↔ ( 𝑁 ∈ ℤ ∧ 𝑀 ≤ 𝑁 ) ) |