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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 +∞ = +

Proof

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