An initial choice is made to generate a basin of attraction field (the default), or any other alternative requiring a seed (the initial network state) to be specified. A basin of attraction field will be seeded automatically, starting with the null state.
Select ``s'' for a ``forward only`` run (i.e. to generate just space-time patterns) or for a single basin or subtree. In this case a seed will be required, and will be set at a later stage in the prompt sequence (see #15).