phase phase#1
participant phase#1:actor#1[0] member=0/3 steps=ask#1
participant phase#1:actor#1[1] member=1/3 steps=ask#1
participant phase#1:actor#1[2] member=2/3 steps=ask#1
phase phase#2
participant phase#2:actor#2 many steps=ask#2
phase phase#3
participant phase#3:actor#3 "writer" steps=ask#3
