I have a question about a notation in Matsumura's "Commutative Algebra". I post below a screenshot of the page in the book in which I encountered it, underlining some instances of the notation. I just don't know what it means, and I haven't been able to find anything like it. Can anyone tell me what it stands for?
Thank you in advance!
It is the ideal quotient. See there for elementary formulas for the ideal quotient.