Levin's comparison theorems for second order nonlinear differential equations and inequalities
The class of linear differential systems with coefficient matrices which are commutative with their integrals is considered. The results on asymptotic equivalence of these systems and their distribution among linear systems are given.
In the paper existence and uniqueness results for the linear differential system on the interval [0,1] with distributional coefficients and solutions from the space of regulated functions are obtained.