Theorem 5lt9

Description: 5 is less than 9. (Contributed by Mario Carneiro, 9-Mar-2015)

	Ref	Expression
Assertion	5lt9	|- 5 < 9

Proof

Step	Hyp	Ref	Expression
1		5lt6	|- 5 < 6
2		6lt9	|- 6 < 9
3		5re	|- 5 e. RR
4		6re	|- 6 e. RR
5		9re	|- 9 e. RR
6	3 4 5	lttri	|- ( ( 5 < 6 /\ 6 < 9 ) -> 5 < 9 )
7	1 2 6	mp2an	|- 5 < 9