let p be Real; ( 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
; 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))
A2:
1 / p > 0
by A1, XREAL_1:141;
let a, b, ap, bp, ab be Real_Sequence; ( ( 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 A3:
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 )
; 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))
A4:
for n being Element of NAT holds 0 <= ap . n
A6:
for n being Element of NAT holds 0 <= bp . n
deffunc H1( Element of NAT ) -> Element of REAL = (abs ((a . $1) + (b . $1))) to_power (p - 1);
consider x being Real_Sequence such that
A8:
for n being Element of NAT holds x . n = H1(n)
from SEQ_1:sch 1();
A9:
1 - 1 < p - 1
by A1, XREAL_1:16;
A10:
for n being Element of NAT holds 0 <= x . n
A12:
for n being Element of NAT holds (x (#) (abs b)) . n = abs ((b . n) * (x . n))
reconsider pp = 1 / p as Real ;
reconsider qq = 1 - pp as Real ;
reconsider q = 1 / qq as Real ;
A14:
qq = 1 / q
by XCMPLX_1:56;
then A15:
(1 / p) + (1 / q) = 1
;
1 / p < 1
by A1, XREAL_1:191;
then A16:
1 - 1 < 1 - pp
by XREAL_1:17;
then A17:
q <> 0
by A14;
then
(((1 * q) + (1 * p)) / (p * q)) * (p * q) = 1 * (p * q)
by A1, A15, XCMPLX_1:117;
then A18:
q + p = p * q
by A1, A17, XCMPLX_1:6, XCMPLX_1:88;
A19:
for n being Element of NAT holds ab . n = (x . n) * (abs ((a . n) + (b . n)))
A23:
for n being Element of NAT holds ab . n <= ((x (#) (abs a)) + (x (#) (abs b))) . n
A25:
0 < q
by A16, A14;
A26:
for n being Element of NAT holds (abs (x . n)) to_power q = ab . n
A30:
for n being Element of NAT holds (x (#) (abs a)) . n = abs ((a . n) * (x . n))
A32:
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))
A35:
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))
; verum