BoolVar c = VariableFactory.bool("c", solver);
BoolVar d = VariableFactory.bool("d", solver);
LogOp root = LogOp.and(LogOp.or(a, b, na), LogOp.or(c, d), LogOp.or(b, nb));
ILogical l = LogicTreeToolBox.toCNF(root, solver);
Assert.assertEquals(l.toString(), "(c or d)");
}