let a, b, c, d be Nat; ( a gcd b = 1 & a * b = c |^ d implies ex e, f being Nat st
( a = e |^ d & b = f |^ d ) )
assume that
A1:
a gcd b = 1
and
A2:
a * b = c |^ d
; ex e, f being Nat st
( a = e |^ d & b = f |^ d )
set e = a gcd c;
a gcd c divides c
by NAT_D:def 5;
then A3:
(a gcd c) |^ d divides c |^ d
by Th19;
a gcd c divides a
by NAT_D:def 5;
then
(a gcd c) gcd b = 1
by A1, Th20, NEWTON:70;
then
((a gcd c) |^ d) gcd b = 1
by Th17;
then
(a gcd c) |^ d divides a
by A2, A3, Th36;
then consider g being Nat such that
A4:
((a gcd c) |^ d) * g = a
by NAT_D:def 3;
reconsider g = g as Element of NAT by ORDINAL1:def 13;
A5:
now A6:
c in REAL
by XREAL_0:def 1;
assume A7:
d <> 0
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then consider d1 being
Nat such that A8:
d = 1
+ d1
by NAT_1:10, NAT_1:14;
reconsider d1 =
d1 as
Element of
NAT by ORDINAL1:def 13;
A9:
d >= 1
by A7, NAT_1:14;
A10:
now assume A11:
a gcd c <> 0
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then A12:
(
a <> 0 or
c <> 0 )
by INT_2:5;
then A13:
a <> 0
by A2, A6, CARD_4:51;
A14:
now reconsider e1 =
a gcd c as
Real by XREAL_0:def 1;
assume A15:
c <> 0
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then consider a1,
c1 being
Integer such that A16:
a = (a gcd c) * a1
and A17:
(a gcd c) * c1 = c
and A18:
a1,
c1 are_relative_prime
by INT_2:38;
reconsider a1 =
a1,
c1 =
c1 as
Element of
NAT by A13, A15, A16, A17, Lm6;
a1 =
(((a gcd c) |^ (d1 + 1)) * g) / (a gcd c)
by A4, A8, A11, A16, XCMPLX_1:90
.=
(((a gcd c) * ((a gcd c) |^ d1)) * g) / (a gcd c)
by NEWTON:11
.=
((a gcd c) * (((a gcd c) |^ d1) * g)) / (a gcd c)
.=
((a gcd c) |^ d1) * g
by A11, XCMPLX_1:90
;
then A19:
g divides a1
by NAT_D:def 3;
a1 gcd c1 = 1
by A18, INT_2:def 4;
then
g gcd c1 = 1
by A19, Th20, NEWTON:70;
then A20:
g gcd (c1 |^ d) = 1
by Th17;
A21:
e1 |^ d <> 0
by A11, CARD_4:51;
c1 = c / (a gcd c)
by A11, A17, XCMPLX_1:90;
then A22:
c1 |^ d =
(((a gcd c) |^ d) * (g * b)) / ((a gcd c) |^ d)
by A2, A4, PREPOWER:15
.=
g * b
by A21, XCMPLX_1:90
;
then
g divides c1 |^ d
by NAT_D:def 3;
then
g = 1
by A20, NEWTON:62;
hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A4, A22;
verum end; now assume
0 = c
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then A23:
b = 0
by A2, A9, A12, NEWTON:16, XCMPLX_1:6;
then
a = 1
by A1, NEWTON:65;
then A24:
a = 1
|^ d
by NEWTON:15;
b = 0 |^ d
by A7, A23, NAT_1:14, NEWTON:16;
hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A24;
verum end; hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A14;
verum end; hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A10;
verum end;
hence
ex e, f being Nat st
( a = e |^ d & b = f |^ d )
by A5; verum