Metamath Proof Explorer


Theorem 7pos

Description: The number 7 is positive. (Contributed by NM, 27-May-1999)

Ref Expression
Assertion 7pos 0 < 7

Proof

Step Hyp Ref Expression
1 6re 6
2 1re 1
3 6pos 0 < 6
4 0lt1 0 < 1
5 1 2 3 4 addgt0ii 0 < 6 + 1
6 df-7 7 = 6 + 1
7 5 6 breqtrri 0 < 7