A process call has the same form as a subroutine call, except that the special syntax PROCESSCALL is used in place of CALL . Process calls are placed in process blocks and process do-loops (defined below) to create concurrently executing processes. A process block has the general form
processes
statement_1
...
statement_n
endprocesses
where 
, and the statements are process calls, process
do-loops , and/or at most one
subroutine call. Statements in a process block execute concurrently. A process block terminates, allowing execution to
proceed to the next executable statement, when all of its constituent
statements terminate.
One of the statements in a process block may be a subroutine call . This is denoted by the use of CALL instead of PROCESSCALL in the process block. The call is executed concurrently with the other processes in the block, but is executed in the current process.
If a process block includes only a single process call, then the PROCESSES and ENDPROCESSES statements can be omitted. Note, however, that since the parent process suspends until the new process completes execution, no additional concurrency is introduced.