In section~#secprogramfunctions#13853> we said that programs were
collections of function definitions and possibly some variable
definitions, too. To guide the division of labor among functions, we also
introduced a rough guideline:
``Formulate auxiliary function definitions
for every dependency between quantities in the problem statement.''
So far the guideline has been reasonably effective, but it is now time to
take a second look at it and to formulate some additional guidance
concerning auxiliary functions.
In the first subsection, we refine our original guideline concerning
auxiliary programs. The suggestions mostly put into words the experiences
that we made with the exercises. The second and third one illustrate two of
the ideas in more depth; the last one is an extended exercise.