Figure 1 illustrates the relationship between the various entities that make up the Language Environment program model.

As Figure 1 shows, each process exists within its own address space. An enclave consists of one main routine with any number of subroutines. External data is available only within the enclave in which it resides. External data items that happen to be identically named in different enclaves reference distinct storage locations; the scope of external data, as described earlier, is the enclave. Threads running in an AMODE 64 environment cannot create new "nested" enclaves.

Figure 1. Overview of the full Language Environment program model