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The Edit Menu

Edit → Undo (Ctrl+Z)

Go back in the result stack.

Edit → Redo (Ctrl+Shift+Z)

Go forward in the result stack.

Edit → Cut (Ctrl+X)

Delete the displayed result and copy it to the clipboard.

Edit → Copy (Ctrl+C)

Copy the displayed result to the clipboard.

Edit → Paste (Ctrl+V)

Insert the cut or copied result in the display.