They are on the Standard toolbar.
http://www.kinook.com/UR/Manual/standardtoolbar.htm
To ensure that toolbar is displayed, go to Tools | Customize | Toolbars' and check 'Standard'. If it was customized and doesn't contain the undo/redo commands, click Reset.
http://www.kinook.com/UR/Manual/hidedisplay.htm
http://www.kinook.com/UR/Manual/resettoolbar.htm