public RelationAtom(Operand left, Comparator cmp, Operand right) { o1 = left; o2 = right; isSatisfiable = true; this.cmp = cmp; if (o1.isVariableNotExist() || o2.isVariableNotExist()) isSatisfiable = false; else if (!isSymbolic()) isSatisfiable = isSatisfyConcreteConstraint(); text = o1.getText() + cmp.toString() + o2.getText(); }