let p be Real; ( 1 <= p implies for rseq being Real_Sequence st rseq rto_power p is summable & (Sum (rseq rto_power p)) to_power (1 / p) = 0 holds
for n being natural number holds rseq . n = 0 )
assume A1:
1 <= p
; for rseq being Real_Sequence st rseq rto_power p is summable & (Sum (rseq rto_power p)) to_power (1 / p) = 0 holds
for n being natural number holds rseq . n = 0
A2:
1 / p > 0
by A1, XREAL_1:141;
let rseq be Real_Sequence; ( rseq rto_power p is summable & (Sum (rseq rto_power p)) to_power (1 / p) = 0 implies for n being natural number holds rseq . n = 0 )
assume that
A3:
rseq rto_power p is summable
and
A4:
(Sum (rseq rto_power p)) to_power (1 / p) = 0
; for n being natural number holds rseq . n = 0
A5:
for i being Element of NAT holds (rseq rto_power p) . i >= 0
then ((Sum (rseq rto_power p)) to_power (1 / p)) to_power p =
(Sum (rseq rto_power p)) to_power ((1 / p) * p)
by A1, A2, A3, HOLDER_1:2, SERIES_1:21
.=
(Sum (rseq rto_power p)) to_power 1
by A1, XCMPLX_1:107
.=
Sum (rseq rto_power p)
by POWER:30
;
then A6:
Sum (rseq rto_power p) = 0
by A1, A4, POWER:def 2;
now let n be
natural number ;
rseq . n = 0 reconsider n9 =
n as
Element of
NAT by ORDINAL1:def 13;
A7:
0 to_power (1 / p) = 0
by A2, POWER:def 2;
(rseq rto_power p) . n9 = (abs (rseq . n9)) to_power p
by Def1;
then A8:
(abs (rseq . n)) to_power p = 0
by A3, A5, A6, RSSPACE:21;
((abs (rseq . n)) to_power p) to_power (1 / p) =
(abs (rseq . n)) to_power (p * (1 / p))
by A1, A2, COMPLEX1:132, HOLDER_1:2
.=
(abs (rseq . n)) to_power 1
by A1, XCMPLX_1:107
.=
abs (rseq . n)
by POWER:30
;
hence
rseq . n = 0
by A8, A7, ABSVALUE:7;
verum end;
hence
for n being natural number holds rseq . n = 0
; verum