Metamath Proof Explorer


Theorem gt0ne0i

Description: Positive means nonzero (useful for ordering theorems involving division). (Contributed by NM, 16-Sep-1999)

Ref Expression
Hypothesis lt2.1 A
Assertion gt0ne0i 0 < A A 0

Proof

Step Hyp Ref Expression
1 lt2.1 A
2 0re 0
3 2 1 ltnei 0 < A A 0