Solution
= Solution
A <ring extension> $A\subseteq B$ is an <integral extension> when every $b\in B$ is an <integral element> over $A$: there is a <monic polynomial>
$$
b^d+a_{d-1}b^{d-1}+\cdots+a_0=0
$$
with all $a_i\in A$.
= Solution
A <ring extension> $A\subseteq B$ is an <integral extension> when every $b\in B$ is an <integral element> over $A$: there is a <monic polynomial>
$$
b^d+a_{d-1}b^{d-1}+\cdots+a_0=0
$$
with all $a_i\in A$.