Let be a polynomial and be maxroot the maximal modulus of the root of . From we may derive a the unitary polynomial such that the roots of have a modulus lower or equal to 1 and if is a root of then maxroot is a root of .
Let which may also be written as where is some fixed point.
Let a range for and let be the mid point of the
range. We consider the square in the complex plane centered at
and whose edge length is . Let be the length of the
half-diagonal of this square.