set f = seq_logn ;
let e be Real; ( e > 0 implies ( seq_logn /" (seq_n^ e) is convergent & lim (seq_logn /" (seq_n^ e)) = 0 ) )
assume
e > 0
; ( seq_logn /" (seq_n^ e) is convergent & lim (seq_logn /" (seq_n^ e)) = 0 )
then reconsider e = e as positive Real ;
set g = seq_n^ e;
set h = seq_logn /" (seq_n^ e);
ex s being Real_Sequence st
( s . 0 = 0 & ( for n being Element of NAT st n > 0 holds
s . n = log (2,(n to_power e)) ) )
then consider p being Real_Sequence such that
A4:
p . 0 = 0
and
A5:
for n being Element of NAT st n > 0 holds
p . n = log (2,(n to_power e))
;
set q = p /" (seq_n^ e);
A6:
p /" (seq_n^ e) is convergent
by A5, Lm10;
A7: 1 =
e / e
by XCMPLX_1:60
.=
e * (1 / e)
;
A8:
for n being Nat holds (seq_logn /" (seq_n^ e)) . n = (1 / e) * ((p /" (seq_n^ e)) . n)
proof
let n be
Nat;
(seq_logn /" (seq_n^ e)) . n = (1 / e) * ((p /" (seq_n^ e)) . n)
A9:
n in NAT
by ORDINAL1:def 12;
A10:
(seq_logn /" (seq_n^ e)) . n = (seq_logn . n) / ((seq_n^ e) . n)
by Lm4;
A11:
(p /" (seq_n^ e)) . n = (p . n) / ((seq_n^ e) . n)
by Lm4;
per cases
( n = 0 or n > 0 )
;
suppose A13:
n > 0
;
(seq_logn /" (seq_n^ e)) . n = (1 / e) * ((p /" (seq_n^ e)) . n)then A14:
n to_power e > 0
by POWER:34;
(seq_logn /" (seq_n^ e)) . n =
(log (2,n)) / ((seq_n^ e) . n)
by A10, A13, Def2, A9
.=
(log (2,(n to_power (e * (1 / e))))) / ((seq_n^ e) . n)
by A7, POWER:25
.=
(log (2,((n to_power e) to_power (1 / e)))) / ((seq_n^ e) . n)
by A13, POWER:33
.=
((1 / e) * (log (2,(n to_power e)))) / ((seq_n^ e) . n)
by A14, POWER:55
.=
((1 / e) * (log (2,(n to_power e)))) * (((seq_n^ e) . n) ")
.=
(1 / e) * ((log (2,(n to_power e))) * (((seq_n^ e) . n) "))
.=
(1 / e) * ((log (2,(n to_power e))) / ((seq_n^ e) . n))
;
hence
(seq_logn /" (seq_n^ e)) . n = (1 / e) * ((p /" (seq_n^ e)) . n)
by A5, A11, A13, A9;
verum end; end;
end;
then A15:
seq_logn /" (seq_n^ e) = (1 / e) (#) (p /" (seq_n^ e))
by SEQ_1:9;
A16:
lim (p /" (seq_n^ e)) = 0
by A5, Lm10;
lim (seq_logn /" (seq_n^ e)) =
lim ((1 / e) (#) (p /" (seq_n^ e)))
by A8, SEQ_1:9
.=
(1 / e) * 0
by A6, A16, SEQ_2:8
;
hence
( seq_logn /" (seq_n^ e) is convergent & lim (seq_logn /" (seq_n^ e)) = 0 )
by A6, A15, SEQ_2:7; verum