OSCILLATION IN 1ST-ORDER NEUTRAL DIFFERENTIAL-EQUATIONS WITH INTEGRALLY SMALL COEFFICIENTS

Consider the neutral differential equation with positive and negative coefficients d/dt[x(t) - R(t)x(t - r)] + P(t)x(t - tau) - Q(t)x(t - delta) = 0. where P, Q, R is-an-element-of C[(t0, infinity), R+], r is-an-element-of (0, infinity), and tau, delta is-an-element-of R+. sufficient conditions for the oscillation of solutions of the above equation without the restriction integral-infinity/t0 [P(s) - Q(s - tau + delta)] ds = infinity. (C) 1994 Academic Press, Inc.