Theorem 1lt5

Description: 1 is less than 5. (Contributed by Mario Carneiro, 15-Sep-2013)

	Ref	Expression
Assertion	1lt5	|- 1 < 5

Proof

Step	Hyp	Ref	Expression
1		1lt4	|- 1 < 4
2		4lt5	|- 4 < 5
3		1re	|- 1 e. RR
4		4re	|- 4 e. RR
5		5re	|- 5 e. RR
6	3 4 5	lttri	|- ( ( 1 < 4 /\ 4 < 5 ) -> 1 < 5 )
7	1 2 6	mp2an	|- 1 < 5