Metamath Proof Explorer


Theorem ralrp

Description: Quantification over positive reals. (Contributed by NM, 12-Feb-2008)

Ref Expression
Assertion ralrp
|- ( A. x e. RR+ ph <-> A. x e. RR ( 0 < x -> ph ) )

Proof

Step Hyp Ref Expression
1 elrp
 |-  ( x e. RR+ <-> ( x e. RR /\ 0 < x ) )
2 1 imbi1i
 |-  ( ( x e. RR+ -> ph ) <-> ( ( x e. RR /\ 0 < x ) -> ph ) )
3 impexp
 |-  ( ( ( x e. RR /\ 0 < x ) -> ph ) <-> ( x e. RR -> ( 0 < x -> ph ) ) )
4 2 3 bitri
 |-  ( ( x e. RR+ -> ph ) <-> ( x e. RR -> ( 0 < x -> ph ) ) )
5 4 ralbii2
 |-  ( A. x e. RR+ ph <-> A. x e. RR ( 0 < x -> ph ) )