-ex relational::eval(int level) const
-{
- if (level==1)
- return this->hold();
-
- if (level == -max_recursion_level)
- throw(std::runtime_error("max recursion level reached"));
-
- return (new relational(lh.eval(level-1),rh.eval(level-1),o))->setflag(status_flags::dynallocated | status_flags::evaluated);
-}
-