Metamath Proof Explorer


Theorem psdcoef

Description: Coefficient of a term of the derivative of a power series. (Contributed by SN, 12-Apr-2025)

Ref Expression
Hypotheses psdffval.s
|- S = ( I mPwSer R )
psdffval.b
|- B = ( Base ` S )
psdffval.d
|- D = { h e. ( NN0 ^m I ) | ( `' h " NN ) e. Fin }
psdffval.i
|- ( ph -> I e. V )
psdffval.r
|- ( ph -> R e. W )
psdfval.x
|- ( ph -> X e. I )
psdval.f
|- ( ph -> F e. B )
psdcoef.k
|- ( ph -> K e. D )
Assertion psdcoef
|- ( ph -> ( ( ( ( I mPSDer R ) ` X ) ` F ) ` K ) = ( ( ( K ` X ) + 1 ) ( .g ` R ) ( F ` ( K oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) )

Proof

Step Hyp Ref Expression
1 psdffval.s
 |-  S = ( I mPwSer R )
2 psdffval.b
 |-  B = ( Base ` S )
3 psdffval.d
 |-  D = { h e. ( NN0 ^m I ) | ( `' h " NN ) e. Fin }
4 psdffval.i
 |-  ( ph -> I e. V )
5 psdffval.r
 |-  ( ph -> R e. W )
6 psdfval.x
 |-  ( ph -> X e. I )
7 psdval.f
 |-  ( ph -> F e. B )
8 psdcoef.k
 |-  ( ph -> K e. D )
9 1 2 3 4 5 6 7 psdval
 |-  ( ph -> ( ( ( I mPSDer R ) ` X ) ` F ) = ( k e. D |-> ( ( ( k ` X ) + 1 ) ( .g ` R ) ( F ` ( k oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) ) )
10 fveq1
 |-  ( k = K -> ( k ` X ) = ( K ` X ) )
11 10 oveq1d
 |-  ( k = K -> ( ( k ` X ) + 1 ) = ( ( K ` X ) + 1 ) )
12 fvoveq1
 |-  ( k = K -> ( F ` ( k oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) = ( F ` ( K oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) )
13 11 12 oveq12d
 |-  ( k = K -> ( ( ( k ` X ) + 1 ) ( .g ` R ) ( F ` ( k oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) = ( ( ( K ` X ) + 1 ) ( .g ` R ) ( F ` ( K oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) )
14 13 adantl
 |-  ( ( ph /\ k = K ) -> ( ( ( k ` X ) + 1 ) ( .g ` R ) ( F ` ( k oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) = ( ( ( K ` X ) + 1 ) ( .g ` R ) ( F ` ( K oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) )
15 ovexd
 |-  ( ph -> ( ( ( K ` X ) + 1 ) ( .g ` R ) ( F ` ( K oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) e. _V )
16 9 14 8 15 fvmptd
 |-  ( ph -> ( ( ( ( I mPSDer R ) ` X ) ` F ) ` K ) = ( ( ( K ` X ) + 1 ) ( .g ` R ) ( F ` ( K oF + ( y e. I |-> if ( y = X , 1 , 0 ) ) ) ) ) )