The full expanded names of the library units and subunits included in a given partition shall be distinct. A call to the main subprogram, if the partition has one. What happens to the result of a main function is also implementation defined. The mechanisms for building and running partitions are implementation defined. The execution of a program consists of the execution of a set of partitions.
Further details are implementation defined.
The execution of a partition starts with the execution of its environment task, ends when the environment task terminates, and includes the executions of all tasks of the partition. If such a task is activated, it is not specified whether the task is awaited prior to termination of the environment task. The implementation shall ensure that all compilation units included in a partition are consistent with one another, and are legal according to the rules of the language. The kind of partition described in this clause is known as an active partition. An implementation is allowed to support other kinds of partitions, with implementation-defined semantics.