      \fitem{rnd_bernoulli}($p$:float), \vImpure. The members of the
      \texttt{@rnd\_\emph{distribution}} family return a random generator
      in the form of an impure function $f$ taking no argument. Each time
      $f$ is called, the value of a random variable following the
      \texttt{\emph{distribution}} distribution is returned. The arguments
      of the \texttt{@rnd\_\emph{distribution}} are the parameters of the
      distribution. Two successive calls to
      \texttt{@rnd\_\emph{distribution}} returns two different random
      generators for the same distribution, that is, generators with
      unrelated seeds.

      \code{@rnd_bernouilli}($p$) returns a boolean random generator with
      a probability $p$ to have a \code{true} value. For example
      \begin{lstlisting}
            $bernouilli := @rnd_bernouilli(0.6)
            $t := [ $bernouilli() | (1000) ] 
      \end{lstlisting} %% $
      produces a tab of 1000 random boolean values with a probability of
      0.6 to be true. 

      

      %%% -------------------------------------------------------

