let n be Nat; for p being Prime st n <> 0 holds
for x, y being positive Nat holds not x * (x + 1) = ((p |^ (2 * n)) * y) * (y + 1)
let p be Prime; ( n <> 0 implies for x, y being positive Nat holds not x * (x + 1) = ((p |^ (2 * n)) * y) * (y + 1) )
assume A1:
n <> 0
; for x, y being positive Nat holds not x * (x + 1) = ((p |^ (2 * n)) * y) * (y + 1)
given x, y being positive Nat such that A2:
x * (x + 1) = ((p |^ (2 * n)) * y) * (y + 1)
; contradiction
A3:
x + 0 < x + 1
by XREAL_1:8;
A4:
x,x + 1 are_coprime
;
p |^ (2 * n) divides (p |^ (2 * n)) * (y * (y + 1))
;
then
( p |^ (2 * n) divides x or p |^ (2 * n) divides x + 1 )
by A2, A4, Th107;
then
( x + 0 >= p |^ (2 * n) or x + 1 >= p |^ (2 * n) )
by NAT_D:7;
then
x + 1 >= p |^ (2 * n)
by A3, XXREAL_0:2;
then A5:
2 * (x + 1) >= 2 * (p |^ (2 * n))
by XREAL_1:64;
A6:
p |^ (2 * n) = (p |^ n) |^ 2
by NEWTON:9;
A7:
(p |^ n) |^ 2 = (p |^ n) ^2
by NEWTON:81;
A8: (((p |^ n) * ((2 * y) + 1)) + ((2 * x) + 1)) * (((p |^ n) * ((2 * y) + 1)) - ((2 * x) + 1)) =
((((p |^ n) * (p |^ n)) * ((2 * y) + 1)) * ((2 * y) + 1)) - ((((4 * ((p |^ n) |^ 2)) * y) * (y + 1)) + 1)
by A2, A6
.=
((p |^ n) ^2) - 1
by A7
;
then A9:
((p |^ n) * ((2 * y) + 1)) - ((2 * x) + 1) >= 0
;
A10:
(p |^ (2 * n)) - 1 = (((p |^ n) * ((2 * y) + 1)) + ((2 * x) + 1)) * (((p |^ n) * ((2 * y) + 1)) - ((2 * x) + 1))
by A6, A8, NEWTON:81;
then A12:
(((p |^ n) * ((2 * y) + 1)) - ((2 * x) + 1)) * (((p |^ n) * ((2 * y) + 1)) + ((2 * x) + 1)) >= 1 * (((p |^ n) * ((2 * y) + 1)) + ((2 * x) + 1))
by XREAL_1:64;
((p |^ n) * ((2 * y) + 1)) + ((2 * x) + 1) > 0 + ((2 * x) + 1)
by XREAL_1:6;
then
(p |^ (2 * n)) - 1 > (2 * x) + 1
by A10, A12, XXREAL_0:2;
then
((p |^ (2 * n)) - 1) + 1 > ((2 * x) + 1) + 1
by XREAL_1:8;
then
1 * (p |^ (2 * n)) > 2 * (p |^ (2 * n))
by A5, XXREAL_0:2;
hence
contradiction
by XREAL_1:64; verum