Hi Sean,

> But MASON already has a procedure for doing exactly that: a ParallelSequence.  
ahh, somehow I didn't spot that, but that seems very much to be what I'm
looking for !

Just one thing, I had a quick look in the manual and where the
ParallelSequence constructor method is described is says "the array
ought not be modified later". But my agents can get killed during the
simulation, so I have to update ParallelSequence correspondingly. Since
ParallelSequence is a subclass of Sequence I thought I could use those
methods to change the content of my ParallelSequences !??

Many thanks,