If we're doing a parallel loop, the sequence active lifeline is not shown.
@startuml
!pragma teoz true
autoactivate on
loop 1 to n
a-> b: hi
end
loop 1 to n
b->c : broken
end
& loop 1 to n
e->f : broken
'end
@enduml
Life line is not activated for participant c & f.
http://www.plantuml.com/plantuml/png/NSwn3i8m40FG_Rx2B31bOEqGzLSkvO2ADbST3WDVJv0OWCMIvJTul5E3RLrajuLULWNDds0q4srqdJW_b0Ql8hAuRpY2ZjuqPPG1rrd4wkblB2bF6532RrO_O8yVOYcVlyZXRSOU_SmB