Metamath Proof Explorer


Theorem dvsid

Description: Derivative of the identity function on the real or complex numbers. (Contributed by Steve Rodriguez, 11-Nov-2015)

Ref Expression
Assertion dvsid
|- ( S e. { RR , CC } -> ( S _D ( _I |` S ) ) = ( S X. { 1 } ) )

Proof

Step Hyp Ref Expression
1 fnresi
 |-  ( _I |` CC ) Fn CC
2 rnresi
 |-  ran ( _I |` CC ) = CC
3 2 eqimssi
 |-  ran ( _I |` CC ) C_ CC
4 df-f
 |-  ( ( _I |` CC ) : CC --> CC <-> ( ( _I |` CC ) Fn CC /\ ran ( _I |` CC ) C_ CC ) )
5 1 3 4 mpbir2an
 |-  ( _I |` CC ) : CC --> CC
6 5 jctr
 |-  ( S e. { RR , CC } -> ( S e. { RR , CC } /\ ( _I |` CC ) : CC --> CC ) )
7 recnprss
 |-  ( S e. { RR , CC } -> S C_ CC )
8 dvid
 |-  ( CC _D ( _I |` CC ) ) = ( CC X. { 1 } )
9 8 dmeqi
 |-  dom ( CC _D ( _I |` CC ) ) = dom ( CC X. { 1 } )
10 1ex
 |-  1 e. _V
11 10 fconst
 |-  ( CC X. { 1 } ) : CC --> { 1 }
12 11 fdmi
 |-  dom ( CC X. { 1 } ) = CC
13 9 12 eqtri
 |-  dom ( CC _D ( _I |` CC ) ) = CC
14 7 13 sseqtrrdi
 |-  ( S e. { RR , CC } -> S C_ dom ( CC _D ( _I |` CC ) ) )
15 ssid
 |-  CC C_ CC
16 14 15 jctil
 |-  ( S e. { RR , CC } -> ( CC C_ CC /\ S C_ dom ( CC _D ( _I |` CC ) ) ) )
17 dvres3
 |-  ( ( ( S e. { RR , CC } /\ ( _I |` CC ) : CC --> CC ) /\ ( CC C_ CC /\ S C_ dom ( CC _D ( _I |` CC ) ) ) ) -> ( S _D ( ( _I |` CC ) |` S ) ) = ( ( CC _D ( _I |` CC ) ) |` S ) )
18 6 16 17 syl2anc
 |-  ( S e. { RR , CC } -> ( S _D ( ( _I |` CC ) |` S ) ) = ( ( CC _D ( _I |` CC ) ) |` S ) )
19 7 resabs1d
 |-  ( S e. { RR , CC } -> ( ( _I |` CC ) |` S ) = ( _I |` S ) )
20 19 oveq2d
 |-  ( S e. { RR , CC } -> ( S _D ( ( _I |` CC ) |` S ) ) = ( S _D ( _I |` S ) ) )
21 8 reseq1i
 |-  ( ( CC _D ( _I |` CC ) ) |` S ) = ( ( CC X. { 1 } ) |` S )
22 xpssres
 |-  ( S C_ CC -> ( ( CC X. { 1 } ) |` S ) = ( S X. { 1 } ) )
23 21 22 syl5eq
 |-  ( S C_ CC -> ( ( CC _D ( _I |` CC ) ) |` S ) = ( S X. { 1 } ) )
24 7 23 syl
 |-  ( S e. { RR , CC } -> ( ( CC _D ( _I |` CC ) ) |` S ) = ( S X. { 1 } ) )
25 18 20 24 3eqtr3d
 |-  ( S e. { RR , CC } -> ( S _D ( _I |` S ) ) = ( S X. { 1 } ) )