Metamath Proof Explorer


Theorem lcomf

Description: A linear-combination sum is a function. (Contributed by Stefan O'Rear, 28-Feb-2015)

Ref Expression
Hypotheses lcomf.f
|- F = ( Scalar ` W )
lcomf.k
|- K = ( Base ` F )
lcomf.s
|- .x. = ( .s ` W )
lcomf.b
|- B = ( Base ` W )
lcomf.w
|- ( ph -> W e. LMod )
lcomf.g
|- ( ph -> G : I --> K )
lcomf.h
|- ( ph -> H : I --> B )
lcomf.i
|- ( ph -> I e. V )
Assertion lcomf
|- ( ph -> ( G oF .x. H ) : I --> B )

Proof

Step Hyp Ref Expression
1 lcomf.f
 |-  F = ( Scalar ` W )
2 lcomf.k
 |-  K = ( Base ` F )
3 lcomf.s
 |-  .x. = ( .s ` W )
4 lcomf.b
 |-  B = ( Base ` W )
5 lcomf.w
 |-  ( ph -> W e. LMod )
6 lcomf.g
 |-  ( ph -> G : I --> K )
7 lcomf.h
 |-  ( ph -> H : I --> B )
8 lcomf.i
 |-  ( ph -> I e. V )
9 4 1 3 2 lmodvscl
 |-  ( ( W e. LMod /\ x e. K /\ y e. B ) -> ( x .x. y ) e. B )
10 9 3expb
 |-  ( ( W e. LMod /\ ( x e. K /\ y e. B ) ) -> ( x .x. y ) e. B )
11 5 10 sylan
 |-  ( ( ph /\ ( x e. K /\ y e. B ) ) -> ( x .x. y ) e. B )
12 inidm
 |-  ( I i^i I ) = I
13 11 6 7 8 8 12 off
 |-  ( ph -> ( G oF .x. H ) : I --> B )