Metamath Proof Explorer


Theorem lflcl

Description: A linear functional value is a scalar. (Contributed by NM, 15-Apr-2014)

Ref Expression
Hypotheses lflf.d
|- D = ( Scalar ` W )
lflf.k
|- K = ( Base ` D )
lflf.v
|- V = ( Base ` W )
lflf.f
|- F = ( LFnl ` W )
Assertion lflcl
|- ( ( W e. Y /\ G e. F /\ X e. V ) -> ( G ` X ) e. K )

Proof

Step Hyp Ref Expression
1 lflf.d
 |-  D = ( Scalar ` W )
2 lflf.k
 |-  K = ( Base ` D )
3 lflf.v
 |-  V = ( Base ` W )
4 lflf.f
 |-  F = ( LFnl ` W )
5 1 2 3 4 lflf
 |-  ( ( W e. Y /\ G e. F ) -> G : V --> K )
6 5 3adant3
 |-  ( ( W e. Y /\ G e. F /\ X e. V ) -> G : V --> K )
7 simp3
 |-  ( ( W e. Y /\ G e. F /\ X e. V ) -> X e. V )
8 6 7 ffvelrnd
 |-  ( ( W e. Y /\ G e. F /\ X e. V ) -> ( G ` X ) e. K )