HP HP-28S - Nested Program Structures

Nested Program Structures
Since a clause in a program structure is like a subprogram, the clause
itself
can contain a program structure. The structure inside the clause
is called
the inner structure, and the structure that contains the clause
is called
the outer structure. The program HSORT (Sort a List)" on page
270 demonstrates nested definite loops.
There is no limit to the levels of nesting, except perhaps your ability
to understand the logic. In some cases it's easier to store the inner
structures in programs and use their names as clauses in the outer
structures.
26: Program Structures 233
1