I have the following question about Macaulay2. How to find all integral elements over a subring?
What I mean is the following. Suppose $A$ is a subring of $B$. How can I find the following set?
$$L=\{x\in B : x \text{ is integral over }A\}$$
Here $B$ is a quotient of polynomial ring over rational numbers (e.g., $\mathbb Q[x,y]/(xy+x-1))$ and $A$ is a subring of $B$. I am also not sure how to declare a subring $A$ inside another ring.
Thank you for your help!