Metamath Proof Explorer


Theorem rehalfcl

Description: Real closure of half. (Contributed by NM, 1-Jan-2006)

Ref Expression
Assertion rehalfcl
|- ( A e. RR -> ( A / 2 ) e. RR )

Proof

Step Hyp Ref Expression
1 2re
 |-  2 e. RR
2 2ne0
 |-  2 =/= 0
3 redivcl
 |-  ( ( A e. RR /\ 2 e. RR /\ 2 =/= 0 ) -> ( A / 2 ) e. RR )
4 1 2 3 mp3an23
 |-  ( A e. RR -> ( A / 2 ) e. RR )