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 e. RR
4		3re	|- 3 e. RR
5		9re	|- 9 e. RR
6	3 4 5	lttri	|- ( ( 2 < 3 /\ 3 < 9 ) -> 2 < 9 )
7	1 2 6	mp2an	|- 2 < 9