Theorem 2lt9

Description: 2 is less than 9. (Contributed by Mario Carneiro, 9-Mar-2015)

	Ref	Expression
Assertion	2lt9	$$⊢2<9$$

Proof

Step	Hyp	Ref	Expression
1		2lt3	$$⊢2<3$$
2		3lt9	$$⊢3<9$$
3		2re	$$⊢2\in ℝ$$
4		3re	$$⊢3\in ℝ$$
5		9re	$$⊢9\in ℝ$$
6	3 4 5	lttri	$$⊢\left(2<3\wedge 3<9\right)\to 2<9$$
7	1 2 6	mp2an	$$⊢2<9$$