OSCILLATION PROPERTIES OF SOLUTIONS FORDIFFERENTIAL EQUATIONS WITHDIFFERENTIAL EQUATIONS WITHUNBOUNDED DELAYS
具有无界时滞的微分方程解的振动性

In the present paper, we are interested in the oscillation properties for functionaldifferential equations of the' forms'i = 1andFirst we show that the result on (l) of Hunt and Yorke can be extended to differential equations with unbounded delays. Secondly, a necessary and sufficient conditionis obtained for the oscillation of all solutions of equation (2).