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 ∈ ℝ
2		1re	⊢ 1 ∈ ℝ
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