Metamath Proof Explorer


Theorem dvmptmul

Description: Function-builder for derivative, product rule. (Contributed by Mario Carneiro, 1-Sep-2014) (Revised by Mario Carneiro, 11-Feb-2015)

Ref Expression
Hypotheses dvmptadd.s φS
dvmptadd.a φxXA
dvmptadd.b φxXBV
dvmptadd.da φdxXAdSx=xXB
dvmptadd.c φxXC
dvmptadd.d φxXDW
dvmptadd.dc φdxXCdSx=xXD
Assertion dvmptmul φdxXACdSx=xXBC+DA

Proof

Step Hyp Ref Expression
1 dvmptadd.s φS
2 dvmptadd.a φxXA
3 dvmptadd.b φxXBV
4 dvmptadd.da φdxXAdSx=xXB
5 dvmptadd.c φxXC
6 dvmptadd.d φxXDW
7 dvmptadd.dc φdxXCdSx=xXD
8 2 fmpttd φxXA:X
9 5 fmpttd φxXC:X
10 4 dmeqd φdomdxXAdSx=domxXB
11 3 ralrimiva φxXBV
12 dmmptg xXBVdomxXB=X
13 11 12 syl φdomxXB=X
14 10 13 eqtrd φdomdxXAdSx=X
15 7 dmeqd φdomdxXCdSx=domxXD
16 6 ralrimiva φxXDW
17 dmmptg xXDWdomxXD=X
18 16 17 syl φdomxXD=X
19 15 18 eqtrd φdomdxXCdSx=X
20 1 8 9 14 19 dvmulf φSDxXA×fxXC=dxXAdSx×fxXC+fdxXCdSx×fxXA
21 ovex dxXCdSxV
22 21 dmex domdxXCdSxV
23 19 22 eqeltrrdi φXV
24 eqidd φxXA=xXA
25 eqidd φxXC=xXC
26 23 2 5 24 25 offval2 φxXA×fxXC=xXAC
27 26 oveq2d φSDxXA×fxXC=dxXACdSx
28 ovexd φxXBCV
29 ovexd φxXDAV
30 23 3 5 4 25 offval2 φdxXAdSx×fxXC=xXBC
31 23 6 2 7 24 offval2 φdxXCdSx×fxXA=xXDA
32 23 28 29 30 31 offval2 φdxXAdSx×fxXC+fdxXCdSx×fxXA=xXBC+DA
33 20 27 32 3eqtr3d φdxXACdSx=xXBC+DA