Arbortext IsoDraw > User's Reference > Menus > Window Menu > Show Object Window > Commands in the Pop-up Menu > Invert Selection
  
Invert Selection
Assume that one or more objects have been selected. If you now select the Invert selection command, all unselected objects will now be selected and all selected objects will be unselected. This command is useful if you want to select the majority of the objects in the window. Select the objects that you do not want to include in your selection and then use the Invert selection command.