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+∞=+