A multivariate polynomial of the form is said to be strict sense stable if it has no roots, such that each of s₁, ..., s_m has a nonnegative real part. In the one-dimensional case, this property is identical to the property of being Hurwitz stable. The definition of a stable polynomial is related to the definition of a strict sense stable polynomial, but, unlike strict sense stability, stability is preserved for sufficiently small perturbations of the coefficients. Although the Hadamard product of two Hurwitz stable polynomials is also Hurwitz stable, it is shown by counterexample that the Hadamard product of two stable bivariate polynomials need not be stable.