Metamath Proof Explorer


Theorem plyrecld

Description: Closure of a polynomial with real coefficients. (Contributed by Thierry Arnoux, 18-Sep-2018)

Ref Expression
Hypotheses plyrecld.1
|- ( ph -> F e. ( Poly ` RR ) )
plyrecld.2
|- ( ph -> X e. RR )
Assertion plyrecld
|- ( ph -> ( F ` X ) e. RR )

Proof

Step Hyp Ref Expression
1 plyrecld.1
 |-  ( ph -> F e. ( Poly ` RR ) )
2 plyrecld.2
 |-  ( ph -> X e. RR )
3 fvres
 |-  ( X e. RR -> ( ( F |` RR ) ` X ) = ( F ` X ) )
4 2 3 syl
 |-  ( ph -> ( ( F |` RR ) ` X ) = ( F ` X ) )
5 plyreres
 |-  ( F e. ( Poly ` RR ) -> ( F |` RR ) : RR --> RR )
6 1 5 syl
 |-  ( ph -> ( F |` RR ) : RR --> RR )
7 6 2 ffvelrnd
 |-  ( ph -> ( ( F |` RR ) ` X ) e. RR )
8 4 7 eqeltrrd
 |-  ( ph -> ( F ` X ) e. RR )