
# process[1]:
event[1]: receive: *[{
  lanes.S?(lanes.s);
  ...
}]
event[2]: receive: *[{
  ...;
  lanes.B[lanes.s]?(lanes.b)
}]

# process[2]:
event[3]: receive: *[{
  hairs.S?(hairs.s);
  ...
}]
event[4]: send: *[{
  ...;
  hairs.B[hairs.s]!(true)
}]
