Variables: 
bool[1]: "a.y.z" 
chan[1]: "x" 

Event graph: 
event[0]: fork: null, #pred: 0, succ: 1 2 

# process[0]:
event[1]: send: x!(true), pid: 0, #pred: 1, succ: 
channel deps: 1 

# process[2]:
event[2]: receive: a.y.a?(a.y.z), pid: 2, #pred: 1, succ: 
channel deps: 1 

