Variables: 
bool[1]: "x" 
bool[2]: "y" 

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

# process[0]:
event[1]: fork: , pid: 0, #pred: 1, succ: 3 2 
event[2]: assign: y := false, pid: 0, #pred: 1, succ: 2 
event[3]: assign: x := true, pid: 0, #pred: 1, succ: 3 

