Description: 1 is less than 10. (Contributed by NM, 7-Nov-2012) (Revised by Mario Carneiro, 9-Mar-2015) (Revised by AV, 8-Sep-2021) (Proof shortened by Umit Teoman Dogan, 10-Jun-2026)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | 1lt10 | ⊢ 1 < ; 1 0 |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 1nn0 | ⊢ 1 ∈ ℕ0 | |
| 2 | 1re | ⊢ 1 ∈ ℝ | |
| 3 | 9re | ⊢ 9 ∈ ℝ | |
| 4 | 1lt9 | ⊢ 1 < 9 | |
| 5 | 2 3 4 | ltleii | ⊢ 1 ≤ 9 |
| 6 | 1 5 | le9lt10 | ⊢ 1 < ; 1 0 |