Arawomo, P. O.2023-03-202023-03-202014-042160-0384ui_art_arawomo_interval_2014Advances in Pure Mathematics 4, pp. 147-155http://ir.library.ui.edu.ng/handle/123456789/8099Without the usual assumption of monotonicity, we establish some results on the theory of hyperbolic differential inequalities which enable us to produce a majorising interval function for the solution of the hyperbolic initial value problem. Using this function, a variation of parameters formula and interval iterative technique, the existence of solution to the problem is established.enInterval FunctionsInterval MajorantInterval ExtensionInterval OperatorNested SequenceArticle