Jacal is a symbolic math package written in Scheme by Aubrey Jaffer. It is usually installed as an extra package in SLIB.
You can use Guile's interface to SLIB to invoke Jacal:
(use-modules (ice-9 slib)) (slib:load "math") (math)
For complete documentation on Jacal, please read the Jacal manual. If it has been installed on line, you can look at Jacal. Otherwise you can find it on the web at http://www-swiss.ai.mit.edu/~jaffer/JACAL.html