theorem :: NEWTON03:1

for k, n being Nat
for a1, b1 being Complex holds (a1 |^ (n + k)) + (b1 |^ (n + k)) = ((a1 |^ n) * ((a1 |^ k) + (b1 |^ k))) + ((b1 |^ k) * ((b1 |^ n) - (a1 |^ n)))