Properties combination in Qt stylesheet

I wrote Qt4 (or Qt5) class MyButton and defined two boolean properties, like this: ``` #include <QPushButton> class MyButton : QPushButton { Q_OBJECT Q_PROPERTY(bool property_1 READ property_1) Q_PROPERTY(bool property_2 READ property_2) public: explicit MyButton(QWidget *parent = 0); ... } ``` Now I want to customize application stylesheet in external file so that in different combinations of this properties MyButton has different background color. Separately this works well: ``` MyButton[property_1="true"] { background-color: black } MyButton[property_2="true"] { background-color: white } ``` So the question is: how to combine few properties in the same condition with "and", "or" and "not" operations?