In the preceding chapters, we often associated interval parameters with either the universal or the existential quantifier: Some LP property should be satisfied for all or for at least one realization of interval coefficients. In this chapter, we introduce \(\forall \exists \) -quantification, which generalizes both cases. First, we consider \(\forall \exists \) -quantified interval systems of linear equations and inequalities, and we study the corresponding \(\forall \exists \) solutions and solvability. Then, we investigate \(\forall \exists \) -quantified LP problems, for which we propose two robust optimization approaches.