Theorem 6lt7

Description: 6 is less than 7. (Contributed by Mario Carneiro, 15-Sep-2013)

	Ref	Expression
Assertion	6lt7	|- 6 < 7

Proof

Step	Hyp	Ref	Expression
1		6re	|- 6 e. RR
2	1	ltp1i	|- 6 < ( 6 + 1 )
3		df-7	|- 7 = ( 6 + 1 )
4	2 3	breqtrri	|- 6 < 7