4 ms·
If you took three semesters of post-secondary maths and never encountered "∈", you should ask for your money back.
by ajarmst 10y ago
If you took three semesters of post-secondary maths and never encountered "∈", you should ask for your money back.
- marssaxman 10y agoI don't know whether I encountered it. Perhaps I just forgot. Either way, it hasn't been a notation used in real life.