let e be positive Real; :: thesis: for f being Real_Sequence st f . 0 = 0 & ( for n being Element of NAT st n > 0 holds
f . n = log 2,(n to_power e) ) holds
( f /" (seq_n^ e) is convergent & lim (f /" (seq_n^ e)) = 0 )
let f be Real_Sequence; :: thesis: ( f . 0 = 0 & ( for n being Element of NAT st n > 0 holds
f . n = log 2,(n to_power e) ) implies ( f /" (seq_n^ e) is convergent & lim (f /" (seq_n^ e)) = 0 ) )
assume A1:
( f . 0 = 0 & ( for n being Element of NAT st n > 0 holds
f . n = log 2,(n to_power e) ) )
; :: thesis: ( f /" (seq_n^ e) is convergent & lim (f /" (seq_n^ e)) = 0 )
set g = seq_n^ e;
set h = f /" (seq_n^ e);
A2:
now let p be
real number ;
:: thesis: ( p > 0 implies ex N being Element of NAT st
for n being Element of NAT st n >= N holds
abs (((f /" (seq_n^ e)) . n) - 0 ) < p )assume A3:
p > 0
;
:: thesis: ex N being Element of NAT st
for n being Element of NAT st n >= N holds
abs (((f /" (seq_n^ e)) . n) - 0 ) < preconsider p1 =
p as
Real by XREAL_0:def 1;
set i0 =
[/((7 / p1) to_power (1 / e))\];
set i1 =
[/((p1 to_power (- (2 / e))) + 1)\];
set N =
max (max [/((7 / p1) to_power (1 / e))\],[/((p1 to_power (- (2 / e))) + 1)\]),2;
A4:
(
max (max [/((7 / p1) to_power (1 / e))\],[/((p1 to_power (- (2 / e))) + 1)\]),2
>= max [/((7 / p1) to_power (1 / e))\],
[/((p1 to_power (- (2 / e))) + 1)\] &
max (max [/((7 / p1) to_power (1 / e))\],[/((p1 to_power (- (2 / e))) + 1)\]),2
>= 2 )
by XXREAL_0:25;
(
max [/((7 / p1) to_power (1 / e))\],
[/((p1 to_power (- (2 / e))) + 1)\] >= [/((7 / p1) to_power (1 / e))\] &
max [/((7 / p1) to_power (1 / e))\],
[/((p1 to_power (- (2 / e))) + 1)\] >= [/((p1 to_power (- (2 / e))) + 1)\] )
by XXREAL_0:25;
then A5:
(
max (max [/((7 / p1) to_power (1 / e))\],[/((p1 to_power (- (2 / e))) + 1)\]),2
>= [/((7 / p1) to_power (1 / e))\] &
max (max [/((7 / p1) to_power (1 / e))\],[/((p1 to_power (- (2 / e))) + 1)\]),2
>= [/((p1 to_power (- (2 / e))) + 1)\] )
by A4, XXREAL_0:2;
max (max [/((7 / p1) to_power (1 / e))\],[/((p1 to_power (- (2 / e))) + 1)\]),2 is
Integer
then reconsider N =
max (max [/((7 / p1) to_power (1 / e))\],[/((p1 to_power (- (2 / e))) + 1)\]),2 as
Element of
NAT by A4, INT_1:16;
p " > 0
by A3;
then
7
* (p " ) > 7
* 0
by XREAL_1:70;
then A6:
7
/ p > 0
;
take N =
N;
:: thesis: for n being Element of NAT st n >= N holds
abs (((f /" (seq_n^ e)) . n) - 0 ) < plet n be
Element of
NAT ;
:: thesis: ( n >= N implies abs (((f /" (seq_n^ e)) . n) - 0 ) < p )assume A7:
n >= N
;
:: thesis: abs (((f /" (seq_n^ e)) . n) - 0 ) < pthen A8:
(
n >= 2 &
n >= [/((7 / p1) to_power (1 / e))\] &
n >= [/((p1 to_power (- (2 / e))) + 1)\] )
by A4, A5, XXREAL_0:2;
[/((7 / p1) to_power (1 / e))\] >= (7 / p) to_power (1 / e)
by INT_1:def 5;
then A9:
n >= (7 / p) to_power (1 / e)
by A8, XXREAL_0:2;
(7 / p1) to_power (1 / e) > 0
by A6, POWER:39;
then
n to_power e >= ((7 / p) to_power (1 / e)) to_power e
by A9, Lm6;
then
n to_power e >= (7 / p1) to_power (e * (1 / e))
by A6, POWER:38;
then
n to_power e >= (7 / p) to_power 1
by XCMPLX_1:107;
then
n to_power e >= 7
/ p1
by POWER:30;
then
p * (n to_power e) >= (7 / p) * p
by A3, XREAL_1:66;
then
p * (n to_power e) >= 7
by A3, XCMPLX_1:88;
then
p * (n to_power e) > 6
by XXREAL_0:2;
then A10:
(p1 * (n to_power e)) ^2 < 2
to_power (p1 * (n to_power e))
by Lm14;
set c =
p1 * (n to_power e);
A11:
n to_power e > 0
by A4, A7, POWER:39;
then A12:
(n to_power e) " > 0
;
p * (n to_power e) > p * 0
by A3, A11, XREAL_1:70;
then
p1 * (n to_power e) < (2 to_power (p1 * (n to_power e))) / (p1 * (n to_power e))
by A10, XREAL_1:83;
then
n to_power e < ((2 to_power (p1 * (n to_power e))) / (p1 * (n to_power e))) / p
by A3, XREAL_1:83;
then A13:
n to_power e < (2 to_power (p1 * (n to_power e))) / ((p1 * (n to_power e)) * p)
by XCMPLX_1:79;
A14:
p1 to_power 2
> 0
by A3, POWER:39;
A15:
[/((p1 to_power (- (2 / e))) + 1)\] >= (p to_power (- (2 / e))) + 1
by INT_1:def 5;
(p to_power (- (2 / e))) + 1
> (p to_power (- (2 / e))) + 0
by XREAL_1:10;
then
[/((p1 to_power (- (2 / e))) + 1)\] > p to_power (- (2 / e))
by A15, XXREAL_0:2;
then A16:
n > p to_power (- (2 / e))
by A8, XXREAL_0:2;
p1 to_power (- (2 / e)) > 0
by A3, POWER:39;
then
n to_power e > (p to_power (- (2 / e))) to_power e
by A16, POWER:42;
then
n to_power e > p1 to_power ((- (2 / e)) * e)
by A3, POWER:38;
then
n to_power e > p to_power (- ((2 / e) * e))
;
then
n to_power e > p to_power (- 2)
by XCMPLX_1:88;
then
(p to_power 2) * (n to_power e) > (p to_power 2) * (p to_power (- 2))
by A14, XREAL_1:70;
then
(p1 to_power 2) * (n to_power e) > p1 to_power (2 + (- 2))
by A3, POWER:32;
then
(p1 to_power 2) * (n to_power e) > 1
by POWER:29;
then
(p1 ^2 ) * (n to_power e) > 1
by POWER:53;
then A17:
1
/ (p * (p1 * (n to_power e))) < 1
/ 1
by XREAL_1:90;
2
to_power (p1 * (n to_power e)) > 0
by POWER:39;
then
(2 to_power (p1 * (n to_power e))) * (1 / ((p1 * (n to_power e)) * p)) < (2 to_power (p1 * (n to_power e))) * (1 / 1)
by A17, XREAL_1:70;
then
(2 to_power (p1 * (n to_power e))) / ((p1 * (n to_power e)) * p) < (2 to_power (p1 * (n to_power e))) * 1
;
then
n to_power e < 2
to_power (p1 * (n to_power e))
by A13, XXREAL_0:2;
then
log 2,
(n to_power e) < log 2,
(2 to_power (p1 * (n to_power e)))
by A11, POWER:65;
then
log 2,
(n to_power e) < (p1 * (n to_power e)) * (log 2,2)
by POWER:63;
then
log 2,
(n to_power e) < (p1 * (n to_power e)) * 1
by POWER:60;
then A18:
(log 2,(n to_power e)) / (n to_power e) < p
by A11, XREAL_1:85;
n > 1
by A8, XXREAL_0:2;
then
n to_power e > n to_power 0
by POWER:44;
then
n to_power e > 1
by POWER:29;
then
log 2,
(n to_power e) > log 2,1
by POWER:65;
then
log 2,
(n to_power e) > 0
by POWER:59;
then
(log 2,(n to_power e)) * ((n to_power e) " ) > 0 * ((n to_power e) " )
by A12, XREAL_1:70;
then A19:
(log 2,(n to_power e)) / (n to_power e) > 0
;
(f /" (seq_n^ e)) . n =
(f . n) / ((seq_n^ e) . n)
by Lm4
.=
(log 2,(n to_power e)) / ((seq_n^ e) . n)
by A1, A4, A7
.=
(log 2,(n to_power e)) / (n to_power e)
by A4, A7, Def3
;
hence
abs (((f /" (seq_n^ e)) . n) - 0 ) < p
by A18, A19, ABSVALUE:def 1;
:: thesis: verum end;
hence
f /" (seq_n^ e) is convergent
by SEQ_2:def 6; :: thesis: lim (f /" (seq_n^ e)) = 0
hence
lim (f /" (seq_n^ e)) = 0
by A2, SEQ_2:def 7; :: thesis: verum