Theorem 4pos

Description: The number 4 is positive. (Contributed by NM, 27-May-1999)

	Ref	Expression
Assertion	4pos	|- 0 < 4

Proof

Step	Hyp	Ref	Expression
1		3re	|- 3 e. RR
2		1re	|- 1 e. RR
3		3pos	|- 0 < 3
4		0lt1	|- 0 < 1
5	1 2 3 4	addgt0ii	|- 0 < ( 3 + 1 )
6		df-4	|- 4 = ( 3 + 1 )
7	5 6	breqtrri	|- 0 < 4