let p be Real; :: thesis: ( 1 < p implies for a, b, ap, bp, ab being Real_Sequence st ( for n being Element of NAT holds
( ap . n = (abs (a . n)) to_power p & bp . n = (abs (b . n)) to_power p & ab . n = (abs ((a . n) + (b . n))) to_power p ) ) holds
for n being Element of NAT holds ((Partial_Sums ab) . n) to_power (1 / p) <= (((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p)) )
assume A1:
1 < p
; :: thesis: for a, b, ap, bp, ab being Real_Sequence st ( for n being Element of NAT holds
( ap . n = (abs (a . n)) to_power p & bp . n = (abs (b . n)) to_power p & ab . n = (abs ((a . n) + (b . n))) to_power p ) ) holds
for n being Element of NAT holds ((Partial_Sums ab) . n) to_power (1 / p) <= (((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p))
let a, b, ap, bp, ab be Real_Sequence; :: thesis: ( ( for n being Element of NAT holds
( ap . n = (abs (a . n)) to_power p & bp . n = (abs (b . n)) to_power p & ab . n = (abs ((a . n) + (b . n))) to_power p ) ) implies for n being Element of NAT holds ((Partial_Sums ab) . n) to_power (1 / p) <= (((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p)) )
assume A2:
for n being Element of NAT holds
( ap . n = (abs (a . n)) to_power p & bp . n = (abs (b . n)) to_power p & ab . n = (abs ((a . n) + (b . n))) to_power p )
; :: thesis: for n being Element of NAT holds ((Partial_Sums ab) . n) to_power (1 / p) <= (((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p))
reconsider pp = 1 / p as Real ;
reconsider qq = 1 - pp as Real ;
reconsider q = 1 / qq as Real ;
1 / p < 1
by A1, XREAL_1:191;
then A3:
1 - 1 < 1 - pp
by XREAL_1:17;
A4:
qq = 1 / q
by XCMPLX_1:56;
then A5:
0 < q
by A3;
A6:
q <> 0
by A3, A4;
A7:
1 / p > 0
by A1, XREAL_1:141;
A8:
1 - 1 < p - 1
by A1, XREAL_1:16;
A9:
(1 / p) + (1 / q) = 1
by A4;
then
(((1 * q) + (1 * p)) / (p * q)) * (p * q) = 1 * (p * q)
by A1, A6, XCMPLX_1:117;
then A10:
q + p = p * q
by A1, A6, XCMPLX_1:6, XCMPLX_1:88;
deffunc H1( Element of NAT ) -> Element of REAL = (abs ((a . $1) + (b . $1))) to_power (p - 1);
consider x being Real_Sequence such that
A11:
for n being Element of NAT holds x . n = H1(n)
from SEQ_1:sch 1();
A12:
for n being Element of NAT holds 0 <= x . n
A14:
for n being Element of NAT holds ab . n = (x . n) * (abs ((a . n) + (b . n)))
A18:
for n being Element of NAT holds ab . n <= ((x (#) (abs a)) + (x (#) (abs b))) . n
A21:
for n being Element of NAT holds (x (#) (abs a)) . n = abs ((a . n) * (x . n))
A23:
for n being Element of NAT holds (x (#) (abs b)) . n = abs ((b . n) * (x . n))
A25:
for n being Element of NAT holds (abs (x . n)) to_power q = ab . n
A29:
for n being Element of NAT holds (Partial_Sums ab) . n <= ((((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p))) * (((Partial_Sums ab) . n) to_power (1 / q))
proof
let n be
Element of
NAT ;
:: thesis: (Partial_Sums ab) . n <= ((((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p))) * (((Partial_Sums ab) . n) to_power (1 / q))
A30:
(Partial_Sums ab) . n <= (Partial_Sums ((x (#) (abs a)) + (x (#) (abs b)))) . n
by A18, SERIES_1:17;
A31:
(Partial_Sums ((x (#) (abs a)) + (x (#) (abs b)))) . n =
((Partial_Sums (x (#) (abs a))) + (Partial_Sums (x (#) (abs b)))) . n
by SERIES_1:8
.=
((Partial_Sums (x (#) (abs a))) . n) + ((Partial_Sums (x (#) (abs b))) . n)
by SEQ_1:11
;
A32:
(Partial_Sums (x (#) (abs a))) . n <= (((Partial_Sums ap) . n) to_power (1 / p)) * (((Partial_Sums ab) . n) to_power (1 / q))
by A1, A2, A9, A21, A25, Th6;
(Partial_Sums (x (#) (abs b))) . n <= (((Partial_Sums bp) . n) to_power (1 / p)) * (((Partial_Sums ab) . n) to_power (1 / q))
by A1, A2, A9, A23, A25, Th6;
then
((Partial_Sums (x (#) (abs a))) . n) + ((Partial_Sums (x (#) (abs b))) . n) <= ((((Partial_Sums ap) . n) to_power (1 / p)) * (((Partial_Sums ab) . n) to_power (1 / q))) + ((((Partial_Sums bp) . n) to_power (1 / p)) * (((Partial_Sums ab) . n) to_power (1 / q)))
by A32, XREAL_1:9;
hence
(Partial_Sums ab) . n <= ((((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p))) * (((Partial_Sums ab) . n) to_power (1 / q))
by A30, A31, XXREAL_0:2;
:: thesis: verum
end;
A33:
for n being Element of NAT holds 0 <= ap . n
A35:
for n being Element of NAT holds 0 <= bp . n
A37:
for n being Element of NAT holds 0 <= ab . n
hence
for n being Element of NAT holds ((Partial_Sums ab) . n) to_power (1 / p) <= (((Partial_Sums ap) . n) to_power (1 / p)) + (((Partial_Sums bp) . n) to_power (1 / p))
; :: thesis: verum