Is a mourner obligated during the seven days of mourning to study permitted topics

Is a mourner obligated to study permitted topics, and is he forbidden from neglecting his studies, or is there no obligation to study permitted topics, but if he wishes to study, he may study permitted topics?

There is an obligation to study Torah, and one who is lenient has what to rely on.

The Ritva writes in Tractate Moed Katan, page 15a: "If you wonder why we say a mourner is forbidden from studying Torah, while there (Sukkah 25a) we say he is obligated in all commandments except for tefillin, it can be said that we do not learn from general rules even if they state 'except,' and here it is obvious that it is forbidden to study Torah as they bring joy to the heart. It can also be said that since he recites the Shema morning and evening, that suffices for him as stated at the end of Menachot (99b), and thus he is not exempt from it." It is evident from the Ritva's words that a mourner is not obligated to study permitted topics at all, otherwise, he would have explained that he is obligated in everything, including studying permitted topics of Torah. (And even the Ritva holds that a mourner is allowed in negative things like Tisha B'Av.) This is also evident from Rashi's words in Tractate Moed Katan, page 21a, where he writes: "And what is said (Sukkah 25a) that a mourner is obligated in all commandments except for tefillin - there it refers to other commandments, but these bring joy." It is evident that he holds that since there is joy, the mourner is completely exempt from the commandment of Torah study. This is also evident from the words of the Shibolei HaLeket, who writes that a mourner does not bless the blessings on the Torah, which shows that he holds he is not obligated in Torah study. (For us who bless the blessings on the Torah, it does not prove that he is obligated in Torah study, as it can be said that he blesses like women who bless. In practice, in the book Mateh Yehuda, chapter 384, and in Kaf HaChaim, chapter 554, it is written that although it is permitted to study negative things on Tisha B'Av, he is not obligated to engage in Torah as he is throughout the year. However, in Moed LeChai, chapter 10, it is written that even on Tisha B'Av there is an obligation to engage in Torah and study negative things, and this is evident from the words of Teshuvot Chacham Tzvi, chapter 100, brought in Pitchei Teshuva, Yoreh Deah, chapter 384, note 1, "where it is written that the reason is because he can study negative things in Jeremiah and the laws of mourning, and therefore on a festival when it is forbidden to study such things, it is permitted to study everything as it is not proper to sit idle, as stated there." This shows that all that was canceled for the mourner from Torah study is only because it is permitted to study permitted topics, which shows that it is an obligation.