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	$$⊢6\in ℝ$$
2	1	ltp1i	$$⊢6<6+1$$
3		df-7	$$⊢7=6+1$$
4	2 3	breqtrri	$$⊢6<7$$