This might be left over from research I did at City College of New York.
I worked on "symbolic integers", that is, allowing Axiom to create and
use "an integer" without specifying which one. The first intended use was
to support symbolic interval arithmetic. More broadly this was an effort to
create "symbolic objects" in general. I was working with Gilbert Baumslag
on Infinite Group Theory support. The funding and the position ran out
and I moved to CMU.