[GiNaC-list] Extension to Boolean Algebra?

Hi, Is there an extension of GiNAC to a boolean algebra? The "relational" class seems to be already a step in this direction, as mathematically it could be evaluated to true or false. We would like to apply GiNaC in a context that involves boolean as well as real-valued expressions. It would be great if boolean expression could be represented, manipulated (expansion to CNF, DNF), and, if possible, parsed from a string. If this has not yet been done but is possible in principle, could we add this extension ourselves? Thanks in advance for any pointers on the subject. Best regards, Goran