Using the result of a proven goal to prove another one

[Mr.SpOOn]

Hi,
I'm wondering is it is possible to use what I get from a proven goal
in another one.

I'm not sure yet about what I'm going to do, but I was thinking that
my program (yes, always the music related one) might interact with the
user through the command line.

One can start where to start from choosing a task from a menu and by
giving some input.
For example, I may input some chords and ask for their scale. As a
result I'll have the list of chord, all the notes in the chords and a
list of possible scales.

At this point, how can I keep these data to use them with another goal?

At the moment I structured the whole application this way:

I have different rule bases, one for chords, one for intervals, one
for the notes. Then I have a main program (main.py) with some
functions. In each function I reset the engine and activate the
necessary rule bases and prove the goal. There is just one goal per
function, at the moment.

Maybe all these are stupid or at least obvious questions, but I'd like
to hear your opinion about the best way to proceed.

Thanks,
Carlo