Scope example, with LINK commands

Figure 1 shows the same five interactive programs described in Current channel example, with LINK commands.

The scope of the X channel—the code from which it can be accessed—is programs A, B, and C.

The scope of the Y channel is programs D and E.

Note that, by the time control is returned to program A by program B, the X channel has been modified—it doesn't contain the same set of containers as when it was created by program A.

Figure 1. The scope of a channel—example showing LINK commands
The picture shows the scenario described in the text.

Table 1 lists the name and scope of the current channel (if any) of each of the five programs shown in Figure 1.

Table 1. The scope of a channel—example with LINK commands
Program Current channel Scope of channel
A None Not applicable
B X A, B, C
C X A, B, C
D None Not applicable
E Y D, E