This is not exactly what you are asking for, but you may find Gosper's ideas on using continued fractions for exact arithmetic useful http://www.inwap.com/pdp1

This is not exactly what you are asking for, but you may find Gosper's ideas on using continued fractions for exact arithmetic useful http://www.inwap.com/pdp10/hbaker/hakmem/cf.html http://www.inwap.com/pdp10/hbaker/hakmem/cf.html http://www.strw.leidenuniv.nl/~gurkan/gosper.pdf http://www.strw.leidenuniv.nl/~gurkan/gosper.pdf I think this would be most naturally implemented in something like LISP, Ruby or Python.