let a, b, c, d be Nat; :: thesis: ( a gcd b = 1 & a * b = c |^ d implies ex e, f being Nat st
( a = e |^ d & b = f |^ d ) )
assume A1:
( a gcd b = 1 & a * b = c |^ d )
; :: thesis: ex e, f being Nat st
( a = e |^ d & b = f |^ d )
set e = a gcd c;
A2:
( a gcd c divides c & a gcd c divides a )
by NAT_D:def 5;
then A3:
(a gcd c) |^ d divides c |^ d
by Th19;
(a gcd c) gcd b = 1
by A1, A2, Th20, NEWTON:70;
then
((a gcd c) |^ d) gcd b = 1
by Th17;
then
(a gcd c) |^ d divides a
by A1, 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;
now assume A7:
d <> 0
;
:: thesis: ex e, f being Nat st
( a = e |^ d & b = f |^ d )then A8:
d >= 1
by NAT_1:14;
consider d1 being
Nat such that A9:
d = 1
+ d1
by A7, NAT_1:10, NAT_1:14;
reconsider d1 =
d1 as
Element of
NAT by ORDINAL1:def 13;
X:
c in REAL
by XREAL_0:def 1;
now assume A13:
a gcd c <> 0
;
:: thesis: ex e, f being Nat st
( a = e |^ d & b = f |^ d )then A14:
(
a <> 0 or
c <> 0 )
by INT_2:5;
then A15:
a <> 0
by A1, X, CARD_4:51;
A16:
now assume
0 = c
;
:: thesis: ex e, f being Nat st
( a = e |^ d & b = f |^ d )then A17:
b = 0
by A1, A8, A14, NEWTON:16, XCMPLX_1:6;
then
a = 1
by A1, NEWTON:65;
then A18:
a = 1
|^ d
by NEWTON:15;
b = 0 |^ d
by A7, A17, NAT_1:14, NEWTON:16;
hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A18;
:: thesis: verum end; now assume A19:
c <> 0
;
:: thesis: ex e, f being Nat st
( a = e |^ d & b = f |^ d )reconsider e1 =
a gcd c as
Real by XREAL_0:def 1;
A20:
e1 |^ d <> 0
by A13, CARD_4:51;
consider a1,
c1 being
Integer such that A21:
(
a = (a gcd c) * a1 &
(a gcd c) * c1 = c &
a1,
c1 are_relative_prime )
by A19, INT_2:38;
reconsider a1 =
a1,
c1 =
c1 as
Element of
NAT by A15, A19, A21, Lm6;
A22:
(
a1 = a / (a gcd c) &
c1 = c / (a gcd c) )
by A13, A21, XCMPLX_1:90;
A23:
a1 gcd c1 = 1
by A21, INT_2:def 4;
a1 =
(((a gcd c) |^ (d1 + 1)) * g) / (a gcd c)
by A4, A9, A13, A21, 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 A13, XCMPLX_1:90
;
then
g divides a1
by NAT_D:def 3;
then
g gcd c1 = 1
by A23, Th20, NEWTON:70;
then A24:
g gcd (c1 |^ d) = 1
by Th17;
A25:
c1 |^ d =
(((a gcd c) |^ d) * (g * b)) / ((a gcd c) |^ d)
by A1, A4, A22, PREPOWER:15
.=
g * b
by A20, XCMPLX_1:90
;
then
g divides c1 |^ d
by NAT_D:def 3;
then
g = 1
by A24, NEWTON:62;
hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A4, A25;
:: thesis: verum end; hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A16;
:: thesis: verum end; hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A10;
:: thesis: verum end;
hence
ex e, f being Nat st
( a = e |^ d & b = f |^ d )
by A5; :: thesis: verum