Theorem 3lt4

Description: 3 is less than 4. (Contributed by Mario Carneiro, 15-Sep-2013)

	Ref	Expression
Assertion	3lt4	|- 3 < 4

Proof

Step	Hyp	Ref	Expression
1		3re	|- 3 e. RR
2	1	ltp1i	|- 3 < ( 3 + 1 )
3		df-4	|- 4 = ( 3 + 1 )
4	2 3	breqtrri	|- 3 < 4