When I solve an equation the Suggestion Bar appears showing the option "apply rules to expr...". When I click on the option, the word "expression" appears followed by a blank bar for entering rules, I suppose. I've seen this for a long time, and have tried a few things without success. I don't even know how to ask the Documentation Center about it because all my questions miss the point and get no answers. What to do here must be obvious to others, yet I do not have a clue. Please explain.
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