phase phase#1
participant phase#1:actor#1[0] member=0/2 steps=ask#1
participant phase#1:actor#1[1] member=1/2 steps=ask#1
phase phase#2
participant phase#2:actor#2[0] member=0/2 steps=ask#2
participant phase#2:actor#2[1] member=1/2 steps=ask#2
phase phase#3
participant phase#3:actor#3 "c" steps=ask#3
phase phase#4
participant phase#4:actor#4 "d" steps=ask#4
