> vertices have to wait for values So computation can not start before I have all the inputs, right? But when I --a vertice-- am doing a computation, I would l

> vertices have to wait for values So computation can not start before I have all the inputs, right? But when I --a vertice-- am doing a computation, I would like to ask for more data from some other component, so that I can complete my calculation. So how could I get such data except as one of my input? But I must have all my inputs already, else I would not be executing. This would then seem to be at the core of the difficulty with data-flow programming. Once a computation of a node has been activated, it can not ask for help from anybody, because it must have all its inputs present before it starts doing its calculation. Does this make sense ???