Metamath Proof Explorer


Theorem 0nrp

Description: Zero is not a positive real. Axiom 9 of Apostol p. 20. (Contributed by NM, 27-Oct-2007)

Ref Expression
Assertion 0nrp ¬ 0 ∈ ℝ+

Proof

Step Hyp Ref Expression
1 0re 0 ∈ ℝ
2 1 ltnri ¬ 0 < 0
3 rpgt0 ( 0 ∈ ℝ+ → 0 < 0 )
4 2 3 mto ¬ 0 ∈ ℝ+