# Numerically solving systems of (first order) linear delay differential equations

I was wondering, how to solve such a system with mathematica? I found the NDsolve function, but in the reference is not mentioned if it is possible to solve a system of equations.

sol = NDSolve[{

ParametricPlot[Evaluate[{y'[t], x'[t]} /. First[sol]], {t, 0, 18}]