Thanks :). I think the resolution to my problem is moving away from infinitesimals. I did learn some calculus, linear algebra, number theory etc. in university,

Thanks :). I think the resolution to my problem is moving away from infinitesimals. I did learn some calculus, linear algebra, number theory etc. in university, but I did it quite superficially, since it didn't feel that relevant to me at that time. Now I feel different.