##Parallel elements
##parallel element side-by-side
##Use the 'parallel' keyword in front of an element to allow subsequent elements be laid out besides it. By default (without 'parallel') subsequent elements have to be at least a bit lower than prior ones.
C: Client;
S: Server;
B: Backend;

parallel B--B: State;
C->S: Remove Req;
S->B: Remove Req;
S<-B: Ack;
parallel B--B: No State;
C<-S: Ack;
C--C: Now we\nhave it;
