\item{Tmax}{a numeric value giving the length of the simulation.}
\item{BIRTH, DEATH}{a (vectorized) function which is the primitive
of \code{birth} or \code{death}. This can be used to speed-up the
\item{Tmax}{a numeric value giving the length of the simulation.}
\item{BIRTH, DEATH}{a (vectorized) function which is the primitive
of \code{birth} or \code{death}. This can be used to speed-up the