Commutative Algebra with a View Toward Algebraic Geometry
《Commutative Algebra with a View Toward Algebraic Geometry》 · 第 253 页 · Section 11.3「Invertible Modules」
We shall compare invertible modules with $R$-submodules of the total quotient ring $K(R)$. These are called fractional ideals of $R$. If $I$ is a finitely generated fractional ideal of $R$, then choosing a common denominator for the generators of $I$ shows that $I$ is isomorphic to an ordinary ideal of $R$.