Metamath Proof Explorer


Theorem rexrp

Description: Quantification over positive reals. (Contributed by Mario Carneiro, 21-May-2014)

Ref Expression
Assertion rexrp
|- ( E. x e. RR+ ph <-> E. x e. RR ( 0 < x /\ ph ) )

Proof

Step Hyp Ref Expression
1 elrp
 |-  ( x e. RR+ <-> ( x e. RR /\ 0 < x ) )
2 1 anbi1i
 |-  ( ( x e. RR+ /\ ph ) <-> ( ( x e. RR /\ 0 < x ) /\ ph ) )
3 anass
 |-  ( ( ( 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 rexbii2
 |-  ( E. x e. RR+ ph <-> E. x e. RR ( 0 < x /\ ph ) )