The following example shows a nested structure with some nested programs that are identified as COMMON.

The following table describes the calling hierarchy for the structure that is shown in the example above. Programs A12, A2, and A3 are identified as COMMON, and the calls associated with them differ.
| This program | Can call these programs | And can be called by these programs |
|---|---|---|
| A | A1, A2, A3 | None |
| A1 | A11, A12, A2, A3 | A |
| A11 | A111, A12, A2, A3 | A1 |
| A111 | A12, A2, A3 | A11 |
| A12 | A2, A3 | A1, A11, A111 |
| A2 | A3 | A, A1, A11, A111, A12, A3 |
| A3 | A2 | A, A1, A11, A111, A12, A2 |
In this example, note that: