Variables: 
int[1]: "X.b" 
int[2]: "Y.b" 
int[3]: "Z.b" 

Event graph: 
event[0]: fork: null, #pred: 0, succ: 1 2 3 

# process[1]:
event[1]: assign: X.b := 123, pid: 1, #pred: 1, succ: 1 

# process[2]:
event[2]: assign: Y.b := 456, pid: 2, #pred: 1, succ: 2 

# process[3]:
event[3]: assign: Z.b := 789, pid: 3, #pred: 1, succ: 3 

