Hi, I have noticed that relational(a,b,==).is_equal(relational(b,a,==)) returns 0 Is this expected behaviour for GiNaC internals? I just want to know whether it is worth to write a patch such that a==b .is_equal(b==a) -> 1 a<b .is_equal(b>a) -> 1 etc. that should be implemented in the method relational::is_equal_same_type right? Regards, Pearu Pearu Peterson <pearu@ioc.ee>, PhD, Researcher Department of Mechanics and Applied Mathematics http://cens.ioc.ee/~pearu/ Institute of Cybernetics at Tallinn Technical University Phone: (+372) 6204168 Akadeemia Rd. 21, 12618 Tallinn ESTONIA Fax: (+372) 6204161 *** the nonvalidity of rigorous causality is necessary and not just consistently possible (Heisenberg, 1925) ***