Quasi-GCD computations

Abstract For univariate polynomials with real or complex coefficients and a given error bound ϵ > 0, h is called a quasi-gcd of f and g, if h is an ϵ-approximate divisor of f and of g and if any (exact) common divisor of f, g is an approximate divisor of h. Extended quasi-gcd computation means to find such h and additional cofactors u, ν such that | uf + νg − h |