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 Th14;
a gcd c divides a
by NAT_D:def 5;
then
(a gcd c) gcd b = 1
by A1, Th15, NEWTON:57;
then
((a gcd c) |^ d) gcd b = 1
by Th12;
then
(a gcd c) |^ d divides a
by A2, A3, Th29;
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 12;
A5:
now ( d <> 0 implies ex e, f being Nat st
( a = e |^ d & b = f |^ d ) )assume A6:
d <> 0
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then consider d1 being
Nat such that A7:
d = 1
+ d1
by NAT_1:10, NAT_1:14;
reconsider d1 =
d1 as
Element of
NAT by ORDINAL1:def 12;
A8:
d >= 1
by A6, NAT_1:14;
A9:
now ( a gcd c <> 0 implies ex e, f being Nat st
( a = e |^ d & b = f |^ d ) )assume A10:
a gcd c <> 0
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then A11:
(
a <> 0 or
c <> 0 )
by INT_2:5;
then A12:
a <> 0
by A2, CARD_4:3;
A13:
now ( c <> 0 implies ex e, f being Nat st
( a = e |^ d & b = f |^ d ) )reconsider e1 =
a gcd c as
Real ;
assume A14:
c <> 0
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then consider a1,
c1 being
Integer such that A15:
a = (a gcd c) * a1
and A16:
(a gcd c) * c1 = c
and A17:
a1,
c1 are_coprime
by INT_2:23;
reconsider a1 =
a1,
c1 =
c1 as
Element of
NAT by A12, A14, A15, A16, Lm6;
a1 =
(((a gcd c) |^ (d1 + 1)) * g) / (a gcd c)
by A4, A7, A10, A15, XCMPLX_1:89
.=
(((a gcd c) * ((a gcd c) |^ d1)) * g) / (a gcd c)
by NEWTON:6
.=
((a gcd c) * (((a gcd c) |^ d1) * g)) / (a gcd c)
.=
((a gcd c) |^ d1) * g
by A10, XCMPLX_1:89
;
then A18:
g divides a1
;
a1 gcd c1 = 1
by A17, INT_2:def 3;
then
g gcd c1 = 1
by A18, Th15, NEWTON:57;
then A19:
g gcd (c1 |^ d) = 1
by Th12;
A20:
e1 |^ d <> 0
by A10, CARD_4:3;
c1 = c / (a gcd c)
by A10, A16, XCMPLX_1:89;
then A21:
c1 |^ d =
(((a gcd c) |^ d) * (g * b)) / ((a gcd c) |^ d)
by A2, A4, PREPOWER:8
.=
g * b
by A20, XCMPLX_1:89
;
then
g divides c1 |^ d
;
then
g = 1
by A19, NEWTON:49;
hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A4, A21;
verum end; now ( 0 = c implies ex e, f being Nat st
( a = e |^ d & b = f |^ d ) )assume
0 = c
;
ex e, f being Nat st
( a = e |^ d & b = f |^ d )then A22:
b = 0
by A2, A8, A11, NEWTON:11, XCMPLX_1:6;
then
a = 1
by A1, NEWTON:52;
then A23:
a = 1
|^ d
;
b = 0 |^ d
by A6, A22, NAT_1:14, NEWTON:11;
hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A23;
verum end; hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A13;
verum end; hence
ex
e,
f being
Nat st
(
a = e |^ d &
b = f |^ d )
by A9;
verum end;
now ( d = 0 implies ex e, f being Nat st
( a = e |^ d & b = f |^ d ) )end;
hence
ex e, f being Nat st
( a = e |^ d & b = f |^ d )
by A5; verum