Per the title, what are some of the oldest books on logic out there with unsolved exercises? Maybe there are some hidden gems from before the 20th century out there.


Update: Doesn't have to be mathematical logic per se. I mean logic at large.



Reference request: Oldest books on logic with unsolved exercises?
The update to the question now asks for "logic at large" -- rather than specifically mathematical logic. Then one can go back to before the 20th century, as in:


* [Studies and exercises in formal logic,](https://archive.org/details/studiesandexerc02keyngoog/page/n29/mode/2up%0A) J.N.Keynes, 1884.
* [Questions and exercises in elementary logic, deductive and
inductive,](https://archive.org/details/questionsandexe02oxongoog/page/n9/mode/2up%20%20) W.H. Forbes and D. Hird, 1875.
* [Exercises in logic,](https://archive.org/details/exercisesinlogic00grayrich/page/n6/mode/2up) J.T. Gray, 1845.
* [Logic; or, The art of reasoning simplified. With exercises on a variety of interesting topics, to guide and develope the reasoning powers of the youthful inquirer after truth](https://archive.org/details/logicorartofreas00park/page/n5/mode/2up), S.E. Parker, 1837.


![](https://ilorentz.org/beenakker/MO/logic_1884.png)


*one exercise from Keynes*


