Variables: 
chan[1]: "work.in" 
chan[2]: "work.out" 

Event graph: 
event[0]: fork: null, #pred: 0, succ: 1 4 

# process[1]:
event[1]: fork: , pid: 1, #pred: 1, succ: 3 2 
event[2]: send: work.out!, pid: 1, #pred: 1, succ: 2 
channel deps: 2 
event[3]: receive: work.in?, pid: 1, #pred: 1, succ: 3 
channel deps: 1 

# process[2]:
event[4]: fork: , pid: 2, #pred: 1, succ: 6 5 
event[5]: send: play.out!, pid: 2, #pred: 1, succ: 5 
channel deps: 1 
event[6]: receive: play.in?, pid: 2, #pred: 1, succ: 6 
channel deps: 2 

