let n be Nat; for g being FinSequence of REAL n
for h being FinSequence of NAT
for F being FinSequence of REAL n st h is one-to-one & rng h c= dom g & F = g * h & ( for i being Element of NAT st i in dom g & not i in rng h holds
g . i = 0* n ) holds
Sum g = Sum F
let g be FinSequence of REAL n; for h being FinSequence of NAT
for F being FinSequence of REAL n st h is one-to-one & rng h c= dom g & F = g * h & ( for i being Element of NAT st i in dom g & not i in rng h holds
g . i = 0* n ) holds
Sum g = Sum F
let h be FinSequence of NAT ; for F being FinSequence of REAL n st h is one-to-one & rng h c= dom g & F = g * h & ( for i being Element of NAT st i in dom g & not i in rng h holds
g . i = 0* n ) holds
Sum g = Sum F
let F be FinSequence of REAL n; ( h is one-to-one & rng h c= dom g & F = g * h & ( for i being Element of NAT st i in dom g & not i in rng h holds
g . i = 0* n ) implies Sum g = Sum F )
assume that
A1:
h is one-to-one
and
A2:
rng h c= dom g
and
A3:
F = g * h
and
A4:
for i being Element of NAT st i in dom g & not i in rng h holds
g . i = 0* n
; Sum g = Sum F
consider h3 being Permutation of (dom h), h2 being FinSequence of NAT such that
A5:
h2 = h * h3
and
A6:
h2 is increasing
and
A7:
dom h = dom h2
and
A8:
rng h = rng h2
by A1, Th13;
dom (g * h) = dom h
by A2, RELAT_1:27;
then reconsider h33 = h3 as Permutation of (dom F) by A3;
reconsider F22 = g * h2 as Function ;
dom F22 =
dom h
by A2, A7, A8, RELAT_1:27
.=
Seg (len h)
by FINSEQ_1:def 3
;
then reconsider F23 = F22 as FinSequence by FINSEQ_1:def 2;
rng F22 c= rng g
by RELAT_1:26;
then
rng F23 c= REAL n
by XBOOLE_1:1;
then reconsider F2 = F23 as FinSequence of REAL n by FINSEQ_1:def 4;
F2 = F (*) h33
by A3, A5, RELAT_1:36;
then
Sum F = Sum F2
by Th20;
hence
Sum g = Sum F
by A2, A4, A6, A8, Th22; verum