I found this paper which runs through the mathematical constructs of the majority of what GH has to offer and then on top of it applies it to architecture by way of analyzing Gehry's work.
By far the most readable, clear, concise and complete work through of the math concepts that GH uses that I have seen.
It is a 334 page long PDF file with excellent graphics.
Not only calculus but I think that GH should also be able to deal with something using mathematical model of statistic and probability, for instance, generate regression line based on scatterplot. However I did really like current organisation of menu via component fields of mathematics. Thanks,