We assume that BAP has just returned the line 'Hello World, I am msg(1,5).' of the previous example.
Now please type in:
> xcall(hello_world) < Hello World, I am msg(2,3) < ;
There may appear something different than 'msg(2,3)'. This depends on the actual topology of your system.
Xcall() is one of the parallel constructs provided with the Client-Server Layer of the BAP operating system. Here it is only important to recognise that it doesn't take a lot of effort to use communication and parallelism within BAP.