Description: 0 is not an element of a finite interval of integers starting at 1. (Contributed by AV, 27-Aug-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 0nelfz1 | ⊢ 0 ∉ ( 1 ... 𝑁 ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 0lt1 | ⊢ 0 < 1 | |
| 2 | 0re | ⊢ 0 ∈ ℝ | |
| 3 | 1re | ⊢ 1 ∈ ℝ | |
| 4 | 2 3 | ltnlei | ⊢ ( 0 < 1 ↔ ¬ 1 ≤ 0 ) | 
| 5 | 1 4 | mpbi | ⊢ ¬ 1 ≤ 0 | 
| 6 | 5 | intnanr | ⊢ ¬ ( 1 ≤ 0 ∧ 0 ≤ 𝑁 ) | 
| 7 | 6 | intnan | ⊢ ¬ ( ( 1 ∈ ℤ ∧ 𝑁 ∈ ℤ ∧ 0 ∈ ℤ ) ∧ ( 1 ≤ 0 ∧ 0 ≤ 𝑁 ) ) | 
| 8 | df-nel | ⊢ ( 0 ∉ ( 1 ... 𝑁 ) ↔ ¬ 0 ∈ ( 1 ... 𝑁 ) ) | |
| 9 | elfz2 | ⊢ ( 0 ∈ ( 1 ... 𝑁 ) ↔ ( ( 1 ∈ ℤ ∧ 𝑁 ∈ ℤ ∧ 0 ∈ ℤ ) ∧ ( 1 ≤ 0 ∧ 0 ≤ 𝑁 ) ) ) | |
| 10 | 8 9 | xchbinx | ⊢ ( 0 ∉ ( 1 ... 𝑁 ) ↔ ¬ ( ( 1 ∈ ℤ ∧ 𝑁 ∈ ℤ ∧ 0 ∈ ℤ ) ∧ ( 1 ≤ 0 ∧ 0 ≤ 𝑁 ) ) ) | 
| 11 | 7 10 | mpbir | ⊢ 0 ∉ ( 1 ... 𝑁 ) |