Solve delay differential equations (DDEs) of neutral type

integrates
a system of delay differential equations of neutral type, that has
the form `sol`

= ddensd(`ddefun`

,`dely`

,`delyp`

,`history`

,`tspan`

)

y '(t) = f(t, y(t), y(dy_{1}),..., y(dy_{p}), y '(dyp_{1}),..., y '(dyp_{q})) | (1) |

*t*is the independent variable representing time.*dy*_{i}is any of*p*solution delays.*dyp*_{j}is any of*q*derivative delays.

For information about the algorithm used in this solver, see Shampine [2].

[1] Paul, C.A.H. “A Test Set of Functional
Differential Equations.” *Numerical Analysis Reports*.
No. 243. Manchester, UK: Math Department, University of Manchester,
1994.

[2] Shampine, L.F. “Dissipative Approximations
to Neutral DDEs.” *Applied Mathematics & Computation*.
Vol. 203, Number 2, 2008, pp. 641–648.