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Description: The upper integers are all nonempty. (Contributed by Glauco Siliprandi, 23-Oct-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | uzn0d.1 | ⊢ ( 𝜑 → 𝑀 ∈ ℤ ) | |
| uzn0d.2 | ⊢ 𝑍 = ( ℤ≥ ‘ 𝑀 ) | ||
| Assertion | uzn0d | ⊢ ( 𝜑 → 𝑍 ≠ ∅ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | uzn0d.1 | ⊢ ( 𝜑 → 𝑀 ∈ ℤ ) | |
| 2 | uzn0d.2 | ⊢ 𝑍 = ( ℤ≥ ‘ 𝑀 ) | |
| 3 | 1 2 | uzidd2 | ⊢ ( 𝜑 → 𝑀 ∈ 𝑍 ) |
| 4 | 3 | ne0d | ⊢ ( 𝜑 → 𝑍 ≠ ∅ ) |