let r be Real; :: thesis: for f1, f2, f3, g1, g2, g3 being PartFunc of REAL,REAL
for t0 being Real st f1 is_differentiable_in t0 & f2 is_differentiable_in t0 & f3 is_differentiable_in t0 & g1 is_differentiable_in t0 & g2 is_differentiable_in t0 & g3 is_differentiable_in t0 & g1 . t0 <> 0 & g2 . t0 <> 0 & g3 . t0 <> 0 holds
VFuncdiff (((r (#) f1) / g1),((r (#) f2) / g2),((r (#) f3) / g3),t0) = r * |[((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2)),((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2)),((((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0))) / ((g3 . t0) ^2))]|

let f1, f2, f3, g1, g2, g3 be PartFunc of REAL,REAL; :: thesis: for t0 being Real st f1 is_differentiable_in t0 & f2 is_differentiable_in t0 & f3 is_differentiable_in t0 & g1 is_differentiable_in t0 & g2 is_differentiable_in t0 & g3 is_differentiable_in t0 & g1 . t0 <> 0 & g2 . t0 <> 0 & g3 . t0 <> 0 holds
VFuncdiff (((r (#) f1) / g1),((r (#) f2) / g2),((r (#) f3) / g3),t0) = r * |[((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2)),((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2)),((((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0))) / ((g3 . t0) ^2))]|

let t0 be Real; :: thesis: ( f1 is_differentiable_in t0 & f2 is_differentiable_in t0 & f3 is_differentiable_in t0 & g1 is_differentiable_in t0 & g2 is_differentiable_in t0 & g3 is_differentiable_in t0 & g1 . t0 <> 0 & g2 . t0 <> 0 & g3 . t0 <> 0 implies VFuncdiff (((r (#) f1) / g1),((r (#) f2) / g2),((r (#) f3) / g3),t0) = r * |[((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2)),((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2)),((((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0))) / ((g3 . t0) ^2))]| )
assume that
A1: ( f1 is_differentiable_in t0 & f2 is_differentiable_in t0 & f3 is_differentiable_in t0 ) and
A2: ( g1 is_differentiable_in t0 & g2 is_differentiable_in t0 & g3 is_differentiable_in t0 ) and
A3: ( g1 . t0 <> 0 & g2 . t0 <> 0 & g3 . t0 <> 0 ) ; :: thesis: VFuncdiff (((r (#) f1) / g1),((r (#) f2) / g2),((r (#) f3) / g3),t0) = r * |[((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2)),((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2)),((((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0))) / ((g3 . t0) ^2))]|
A4: ( r (#) f1 is_differentiable_in t0 & r (#) f2 is_differentiable_in t0 & r (#) f3 is_differentiable_in t0 ) by A1, FDIFF_1:15;
then VFuncdiff (((r (#) f1) / g1),((r (#) f2) / g2),((r (#) f3) / g3),t0) = |[((((diff ((r (#) f1),t0)) * (g1 . t0)) - ((diff (g1,t0)) * ((r (#) f1) . t0))) / ((g1 . t0) ^2)),(diff (((r (#) f2) / g2),t0)),(diff (((r (#) f3) / g3),t0))]| by A2, A3, FDIFF_2:14
.= |[((((diff ((r (#) f1),t0)) * (g1 . t0)) - ((diff (g1,t0)) * ((r (#) f1) . t0))) / ((g1 . t0) ^2)),((((diff ((r (#) f2),t0)) * (g2 . t0)) - ((diff (g2,t0)) * ((r (#) f2) . t0))) / ((g2 . t0) ^2)),(diff (((r (#) f3) / g3),t0))]| by A2, A3, A4, FDIFF_2:14
.= |[((((diff ((r (#) f1),t0)) * (g1 . t0)) - ((diff (g1,t0)) * ((r (#) f1) . t0))) / ((g1 . t0) ^2)),((((diff ((r (#) f2),t0)) * (g2 . t0)) - ((diff (g2,t0)) * ((r (#) f2) . t0))) / ((g2 . t0) ^2)),((((diff ((r (#) f3),t0)) * (g3 . t0)) - ((diff (g3,t0)) * ((r (#) f3) . t0))) / ((g3 . t0) ^2))]| by A2, A3, A4, FDIFF_2:14
.= |[((((r * (diff (f1,t0))) * (g1 . t0)) - ((diff (g1,t0)) * ((r (#) f1) . t0))) / ((g1 . t0) ^2)),((((diff ((r (#) f2),t0)) * (g2 . t0)) - ((diff (g2,t0)) * ((r (#) f2) . t0))) / ((g2 . t0) ^2)),((((diff ((r (#) f3),t0)) * (g3 . t0)) - ((diff (g3,t0)) * ((r (#) f3) . t0))) / ((g3 . t0) ^2))]| by A1, FDIFF_1:15
.= |[((((r * (diff (f1,t0))) * (g1 . t0)) - ((diff (g1,t0)) * ((r (#) f1) . t0))) / ((g1 . t0) ^2)),((((r * (diff (f2,t0))) * (g2 . t0)) - ((diff (g2,t0)) * ((r (#) f2) . t0))) / ((g2 . t0) ^2)),((((diff ((r (#) f3),t0)) * (g3 . t0)) - ((diff (g3,t0)) * ((r (#) f3) . t0))) / ((g3 . t0) ^2))]| by A1, FDIFF_1:15
.= |[((((r * (diff (f1,t0))) * (g1 . t0)) - ((diff (g1,t0)) * ((r (#) f1) . t0))) / ((g1 . t0) ^2)),((((r * (diff (f2,t0))) * (g2 . t0)) - ((diff (g2,t0)) * ((r (#) f2) . t0))) / ((g2 . t0) ^2)),((((r * (diff (f3,t0))) * (g3 . t0)) - ((diff (g3,t0)) * ((r (#) f3) . t0))) / ((g3 . t0) ^2))]| by A1, FDIFF_1:15
.= |[((((r * (diff (f1,t0))) * (g1 . t0)) - ((diff (g1,t0)) * (r * (f1 . t0)))) / ((g1 . t0) ^2)),((((r * (diff (f2,t0))) * (g2 . t0)) - ((diff (g2,t0)) * ((r (#) f2) . t0))) / ((g2 . t0) ^2)),((((r * (diff (f3,t0))) * (g3 . t0)) - ((diff (g3,t0)) * ((r (#) f3) . t0))) / ((g3 . t0) ^2))]| by VALUED_1:6
.= |[((((r * (diff (f1,t0))) * (g1 . t0)) - ((diff (g1,t0)) * (r * (f1 . t0)))) / ((g1 . t0) ^2)),((((r * (diff (f2,t0))) * (g2 . t0)) - ((diff (g2,t0)) * (r * (f2 . t0)))) / ((g2 . t0) ^2)),((((r * (diff (f3,t0))) * (g3 . t0)) - ((diff (g3,t0)) * ((r (#) f3) . t0))) / ((g3 . t0) ^2))]| by VALUED_1:6
.= |[((((r * (diff (f1,t0))) * (g1 . t0)) - ((diff (g1,t0)) * (r * (f1 . t0)))) / ((g1 . t0) ^2)),((((r * (diff (f2,t0))) * (g2 . t0)) - ((diff (g2,t0)) * (r * (f2 . t0)))) / ((g2 . t0) ^2)),((((r * (diff (f3,t0))) * (g3 . t0)) - ((diff (g3,t0)) * (r * (f3 . t0)))) / ((g3 . t0) ^2))]| by VALUED_1:6
.= |[((r * (((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0)))) / ((g1 . t0) ^2)),((r * (((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0)))) / ((g2 . t0) ^2)),((r * (((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0)))) / ((g3 . t0) ^2))]|
.= |[(r * ((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2))),((r * (((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0)))) / ((g2 . t0) ^2)),((r * (((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0)))) / ((g3 . t0) ^2))]| by XCMPLX_1:74
.= |[(r * ((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2))),(r * ((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2))),((r * (((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0)))) / ((g3 . t0) ^2))]| by XCMPLX_1:74
.= |[(r * ((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2))),(r * ((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2))),(r * ((((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0))) / ((g3 . t0) ^2)))]| by XCMPLX_1:74
.= r * |[((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2)),((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2)),((((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0))) / ((g3 . t0) ^2))]| by Lm6 ;
hence VFuncdiff (((r (#) f1) / g1),((r (#) f2) / g2),((r (#) f3) / g3),t0) = r * |[((((diff (f1,t0)) * (g1 . t0)) - ((diff (g1,t0)) * (f1 . t0))) / ((g1 . t0) ^2)),((((diff (f2,t0)) * (g2 . t0)) - ((diff (g2,t0)) * (f2 . t0))) / ((g2 . t0) ^2)),((((diff (f3,t0)) * (g3 . t0)) - ((diff (g3,t0)) * (f3 . t0))) / ((g3 . t0) ^2))]| ; :: thesis: verum