How to Toggle the Bool value in XML in Android

In my android app, I've defined a bool value:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <bool name="booleanvalue">false</bool>
</resources>

I'm using it to show or hide a menu function in my menu.xml:

<item
    android:id="@+id/menu1"
    android:icon="@drawable/menu_on"
    android:showAsAction="ifRoom"
    android:title="@string/show_menu1"
    android:visible="@bool/booleanvalue"
    />

However is it possible to get the negative value of the Boolean in the menu.xml without changing the original value?

I want it because there is another menu item which gets hidden when this menu 1 is displayed.