let n be non empty Element of NAT ; for i being Element of NAT
for g being PartFunc of (REAL n),REAL
for y being Element of REAL n
for g1 being PartFunc of (REAL n),(REAL 1) st g1 = <>* g & g1 is_partial_differentiable_in y,i holds
partdiff g1,y,i = <*(partdiff g,y,i)*>
let i be Element of NAT ; for g being PartFunc of (REAL n),REAL
for y being Element of REAL n
for g1 being PartFunc of (REAL n),(REAL 1) st g1 = <>* g & g1 is_partial_differentiable_in y,i holds
partdiff g1,y,i = <*(partdiff g,y,i)*>
let g be PartFunc of (REAL n),REAL ; for y being Element of REAL n
for g1 being PartFunc of (REAL n),(REAL 1) st g1 = <>* g & g1 is_partial_differentiable_in y,i holds
partdiff g1,y,i = <*(partdiff g,y,i)*>
let y be Element of REAL n; for g1 being PartFunc of (REAL n),(REAL 1) st g1 = <>* g & g1 is_partial_differentiable_in y,i holds
partdiff g1,y,i = <*(partdiff g,y,i)*>
let g1 be PartFunc of (REAL n),(REAL 1); ( g1 = <>* g & g1 is_partial_differentiable_in y,i implies partdiff g1,y,i = <*(partdiff g,y,i)*> )
assume that
A1:
g1 = <>* g
and
A2:
g1 is_partial_differentiable_in y,i
; partdiff g1,y,i = <*(partdiff g,y,i)*>
reconsider y9 = y as Point of (REAL-NS n) by REAL_NS1:def 4;
the carrier of (REAL-NS 1) = REAL 1
by REAL_NS1:def 4;
then reconsider h = g1 as PartFunc of (REAL-NS n),(REAL-NS 1) by REAL_NS1:def 4;
A3:
h is_partial_differentiable_in y9,i
by A2, Th16;
then
(partdiff h,y9,i) . <*1*> = partdiff g1,y,i
by Th17;
hence
partdiff g1,y,i = <*(partdiff g,y,i)*>
by A1, A3, Th15; verum