All operations performed in layout mode can be undone, including the Undo operation itself (Redo). After the completion of every operation, the first item in the Edit menu becomes available and has a generic label which indicates the class of operation which can be undone. For example, after a duplicate operation, the menu item label is "Undo Add", as duplicate belongs to the generic class of "add" type operations (as does Paste). If an operation is undone, the menu item label becomes "Redo <Operation>" (e.g. Redo Add). Undo for the previous operation becomes unavailable as soon as the next operation is commenced. If the next operation is canceled before it is completed, the Undo item is unavailable.