Description: 6 is less than 9. (Contributed by Mario Carneiro, 9-Mar-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | 6lt9 | ⊢ 6 < 9 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 6lt7 | ⊢ 6 < 7 | |
2 | 7lt9 | ⊢ 7 < 9 | |
3 | 6re | ⊢ 6 ∈ ℝ | |
4 | 7re | ⊢ 7 ∈ ℝ | |
5 | 9re | ⊢ 9 ∈ ℝ | |
6 | 3 4 5 | lttri | ⊢ ( ( 6 < 7 ∧ 7 < 9 ) → 6 < 9 ) |
7 | 1 2 6 | mp2an | ⊢ 6 < 9 |