The Rewind, Undo, Redo etc buttons at the foot of the Input Tab enable you to inspect all the input that is entered via the Input Tab. Used in this way, the Rewind button allows you to present input as a sequence of 'pages' that you can recover and review. Beware that if you edit the content of a previously input page then the following pages of input will no longer be stored. In effect, the pages trace a path of input where, if you return to previous point and make a change, you are tracing out a new path from that point onwards, If you do want to edit definitions that are recorded in a previously input page, you should use the Rewind, Undo, Redo etc buttons to navigate to the page but then copy-and-paste (Cntrl-C / Cntrl-V) the content of that page into your most recent (or new) instance of the Input Tab.