Description: 5 does not divide 6. (Contributed by AV, 8-Sep-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 5ndvds6 | ⊢ ¬ 5 ∥ 6 | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | 5nn | ⊢ 5 ∈ ℕ | |
| 2 | 1nn0 | ⊢ 1 ∈ ℕ0 | |
| 3 | 1nn | ⊢ 1 ∈ ℕ | |
| 4 | 5cn | ⊢ 5 ∈ ℂ | |
| 5 | 4 | mulridi | ⊢ ( 5 · 1 ) = 5 | 
| 6 | 5 | oveq1i | ⊢ ( ( 5 · 1 ) + 1 ) = ( 5 + 1 ) | 
| 7 | 5p1e6 | ⊢ ( 5 + 1 ) = 6 | |
| 8 | 6 7 | eqtri | ⊢ ( ( 5 · 1 ) + 1 ) = 6 | 
| 9 | 1lt5 | ⊢ 1 < 5 | |
| 10 | 1 2 3 8 9 | ndvdsi | ⊢ ¬ 5 ∥ 6 |