Step |
Hyp |
Ref |
Expression |
1 |
|
kbfval |
|- ( ( A e. ~H /\ B e. ~H ) -> ( A ketbra B ) = ( x e. ~H |-> ( ( x .ih B ) .h A ) ) ) |
2 |
1
|
fveq1d |
|- ( ( A e. ~H /\ B e. ~H ) -> ( ( A ketbra B ) ` C ) = ( ( x e. ~H |-> ( ( x .ih B ) .h A ) ) ` C ) ) |
3 |
|
oveq1 |
|- ( x = C -> ( x .ih B ) = ( C .ih B ) ) |
4 |
3
|
oveq1d |
|- ( x = C -> ( ( x .ih B ) .h A ) = ( ( C .ih B ) .h A ) ) |
5 |
|
eqid |
|- ( x e. ~H |-> ( ( x .ih B ) .h A ) ) = ( x e. ~H |-> ( ( x .ih B ) .h A ) ) |
6 |
|
ovex |
|- ( ( C .ih B ) .h A ) e. _V |
7 |
4 5 6
|
fvmpt |
|- ( C e. ~H -> ( ( x e. ~H |-> ( ( x .ih B ) .h A ) ) ` C ) = ( ( C .ih B ) .h A ) ) |
8 |
2 7
|
sylan9eq |
|- ( ( ( A e. ~H /\ B e. ~H ) /\ C e. ~H ) -> ( ( A ketbra B ) ` C ) = ( ( C .ih B ) .h A ) ) |
9 |
8
|
3impa |
|- ( ( A e. ~H /\ B e. ~H /\ C e. ~H ) -> ( ( A ketbra B ) ` C ) = ( ( C .ih B ) .h A ) ) |