Metamath Proof Explorer


Theorem absgt0i

Description: The absolute value of a nonzero number is positive. Remark in Apostol p. 363. (Contributed by NM, 1-Oct-1999)

Ref Expression
Hypothesis absvalsqi.1 ⊢ A ∈ ℂ
Assertion absgt0i ⊢ A ≠ 0 ↔ 0 < A

Proof

Step Hyp Ref Expression
1 absvalsqi.1 ⊢ A ∈ ℂ
2 absgt0 ⊢ A ∈ ℂ → A ≠ 0 ↔ 0 < A
3 1 2 ax-mp ⊢ A ≠ 0 ↔ 0 < A