Is there a way to log the terminal output to a .txt file?

curry(`?[]`,f)([1]);
                                                  

There is a builtin command "callback". It exists both in Maple 5 and today's Maple. There is no documentation on it. What is it? Why does it exist? Is there any code that uses it?

Does Maple have a way to upload a screenshot of a worksheet or a savefile of a worksheet to MaplePrimes?

What Maple type should I use so that test1 and test2 are always equal? (I use Maple 2017)