ABSTRACT. The verification of an appropriately stated equicontinuity condition for a sequence of solution spaces is one of the two key points in the theory of the Cauchy problem for equations with singular right-hand sides. We obtain a related sufficient condition.KEY WORDS: Cauchy problem for equations with discontinuous right-hand side, generalized differential equations, convergence of solutions.In [1][2][3], a new approach to the theory of ordinary differential equations was initiated. In particular, this approach is aimed at studying differential equations with discontinuous right-hand side and the corresponding generalized differential equations and is based on systematic use of the topological structures introduced in [1][2][3]. This approach was further developed in [4][5][6][7][8][9]. It turns out that the central notion of the theory is that of convergence of sequences of solution spaces, which is adequate to the idea of continuous dependence of solutions on the parameters occurring in the equations. Thus, it is important to study sufficient conditions for convergence. The general outline of the convergence proof is discussed in [3,4,[7][8][9]. The aim of the present paper is to obtain a conveniently verifiable condition for the equicontinuity of a sequence of solution spaces, which is one of the two key points in the convergence proof. The place of our result in the theory is similar to that of Theorem 4 in [3] and Theorem 1 in [4].We use some notation from [1-9] without additional explanations. Let U be an open subset of the product ]~ x R = . We consider the class of set-valued mappings F: U -* R n satisfying the following condition:(1) the values of F are nonempty convex (one-sided) cones with vertex at the origin (note that {0} is an admissible value).Before proceeding to the main part of our exposition, we choose (2) set-valued mappings F, Fi: U ~ R '~, i = 1, 2,..., each of which satisfies condition (1), and moreover, (3) for any point x E U one has F(z) ~_ rq{cc (U{F,(Ox) : i= k, lc + 1, ... } U F(Oz) (5) Gi(t, y) = Fi(t, y) + Si(t) = {u + v: u E Fi(t, y), v E Si(t) } for (t, y) E U, i = 1,2, ....Let V be a cone with vertex at the origin, and let e > 0. Then by Pc we denote the e-neighborhood of the set {u: u E Y, IluH = 1} on the unit sphere S, and by V~ we denote the cone