let a, b, n be Nat; ( a > 0 implies (a |^ (n + 2)) + (a |^ (n + 2)) <> b |^ (n + 2) )
assume A1:
a > 0
; (a |^ (n + 2)) + (a |^ (n + 2)) <> b |^ (n + 2)
assume
not (a |^ (n + 2)) + (a |^ (n + 2)) <> b |^ (n + 2)
; contradiction
then consider j, k, l being Nat such that
A3:
( (j |^ (n + 2)) + (k |^ (n + 2)) = l |^ (n + 2) & j,k are_coprime & j,l are_coprime & k,l are_coprime & a = (a gcd a) * j & a = (a gcd a) * k & b = (a gcd a) * l )
by A1, Th41;
( k * a = 1 * a & j * a = 1 * a )
by NAT_D:32, A3;
then
( k = 1 & j = 1 )
by A1, XCMPLX_1:5;
hence
contradiction
by A3, Lm60; verum