let n be non zero natural number ; :: thesis: Radical n divides n
defpred S1[ natural number ] means for n being non zero natural number st support (PFactors n) c= Seg $1 holds
Radical n divides n;
A1:
S1[ 0 ]
A3:
for k being natural number st S1[k] holds
S1[k + 1]
proof
let k be
natural number ;
:: thesis: ( S1[k] implies S1[k + 1] )
assume A4:
S1[
k]
;
:: thesis: S1[k + 1]
let n be non
zero natural number ;
:: thesis: ( support (PFactors n) c= Seg (k + 1) implies Radical n divides n )
assume A5:
support (PFactors n) c= Seg (k + 1)
;
:: thesis: Radical n divides n
A6:
support (pfexp n) = support (PFactors n)
by Def6;
per cases
( not support (PFactors n) c= Seg k or support (PFactors n) c= Seg k )
;
suppose A7:
not
support (PFactors n) c= Seg k
;
:: thesis: Radical n divides nset p =
k + 1;
set e =
(k + 1) |-count n;
set s =
(k + 1) |^ ((k + 1) |-count n);
A13:
k + 1 is
Prime
by A6, A8, NAT_3:34;
then A14:
(pfexp n) . (k + 1) = (k + 1) |-count n
by NAT_3:def 8;
A15:
k + 1
> 1
by A13, INT_2:def 5;
then
(k + 1) |^ ((k + 1) |-count n) divides n
by NAT_3:def 7;
then consider t being
Nat such that A16:
n = ((k + 1) |^ ((k + 1) |-count n)) * t
by NAT_D:def 3;
reconsider s =
(k + 1) |^ ((k + 1) |-count n),
t =
t as non
zero natural number by A16;
A17:
support (PFactors t) c= Seg k
A26:
(k + 1) |-count n <> 0
by A6, A8, A14, POLYNOM1:def 7;
A27:
support (ppf s) = support (pfexp s)
by NAT_3:def 9;
then A28:
support (ppf s) = {(k + 1)}
by A13, A26, NAT_3:42;
then A29:
support (PFactors s) = {(k + 1)}
by A27, Def6;
reconsider s1 =
s,
t1 =
t as non
zero Element of
NAT by ORDINAL1:def 13;
A34:
s1,
t1 are_relative_prime
proof
assume
not
s1,
t1 are_relative_prime
;
:: thesis: contradiction
then A35:
s1 gcd t1 <> 1
by INT_2:def 4;
set u =
s1 gcd t1;
A36:
s1 gcd t1 divides s1
by NAT_D:def 5;
s1 gcd t1 <> 0
by INT_2:5;
then
0 < s1 gcd t1
;
then
0 + 1
<= s1 gcd t1
by NAT_1:13;
then
s1 gcd t1 > 1
by A35, XXREAL_0:1;
then
s1 gcd t1 >= 1
+ 1
by NAT_1:13;
then consider r being
Element of
NAT such that A37:
r is
prime
and A38:
r divides s1 gcd t1
by INT_2:48;
r divides s1
by A36, A38, NAT_D:4;
then
r divides k + 1
by A37, NAT_3:5;
then A39:
(
r = 1 or
r = k + 1 )
by A13, INT_2:def 5;
s1 gcd t1 divides t1
by NAT_D:def 5;
then
k + 1
divides t1
by A37, A38, A39, INT_2:def 5, NAT_D:4;
then
k + 1
in support (pfexp t)
by A13, NAT_3:37;
then
k + 1
in support (PFactors t)
by Def6;
then
k + 1
<= k
by A17, FINSEQ_1:3;
hence
contradiction
by NAT_1:13;
:: thesis: verum
end; consider f being
FinSequence of
COMPLEX such that A40:
Product (PFactors s) = Product f
and A41:
f = (PFactors s) * (canFS (support (PFactors s)))
by NAT_3:def 5;
A42:
dom (PFactors s) = SetPrimes
by PARTFUN1:def 4;
A43:
k + 1
in support (pfexp s)
by A27, A28, TARSKI:def 1;
f =
(PFactors s) * <*(k + 1)*>
by A29, A41, UPROOTS:6
.=
<*((PFactors s) . (k + 1))*>
by A8, A42, CIRCCMB3:36
;
then A44:
Product (PFactors s) =
(PFactors s) . (k + 1)
by A40, RVSUM_1:125
.=
k + 1
by A43, Def6
;
support (ppf t) = support (pfexp t)
by NAT_3:def 9;
then A45:
(
support (ppf s) = support (PFactors s) &
support (ppf t) = support (PFactors t) )
by A27, Def6;
A46:
(
Radical s divides s &
Radical t divides t )
by A4, A17, A26, A44, NAT_3:3;
Radical n =
Product ((PFactors s) + (PFactors t))
by A16, A34, Th50
.=
(Radical s) * (Radical t)
by A30, A45, NAT_3:19
;
hence
Radical n divides n
by A16, A46, NAT_3:1;
:: thesis: verum end; end;
end;
A47:
for k being natural number holds S1[k]
from NAT_1:sch 2(A1, A3);
consider mS being Element of NAT such that
A48:
support (ppf n) c= Seg mS
by Th14;
support (ppf n) =
support (pfexp n)
by NAT_3:def 9
.=
support (PFactors n)
by Def6
;
hence
Radical n divides n
by A47, A48; :: thesis: verum