how can we know what that is? jBPM has fork nodes out of the box
yes, the question was how do i :
1. advance to the node under the fork ? by pi.signal() ?
2. why don't i get the task under the fork as unfinished task ?
the your subject was completely misleading
1: no, you normally signal tasks or tokens. How should the processinstance know which token in the fork to signal when it just gets signalled itself. See the testcases in the source how thing can be done
2: no idea... are there any tasks at all?