Metamath Proof Explorer


Theorem ioorp

Description: The set of positive reals expressed as an open interval. (Contributed by Steve Rodriguez, 25-Nov-2007)

Ref Expression
Assertion ioorp ⊢ 0 +∞ = ℝ +

Proof

Step Hyp Ref Expression
1 ioopos ⊢ 0 +∞ = x ∈ ℝ | 0 < x
2 df-rp ⊢ ℝ + = x ∈ ℝ | 0 < x
3 1 2 eqtr4i ⊢ 0 +∞ = ℝ +