Solitons: Differential equations, symmetries, and infinite-dimensional algebras
《Solitons: Differential equations, symmetries, and infinite-dimensional algebras》 · 第 129 页 · Theorem 5.22(4)
Let $f:Y\to X$ be a morphism of $k$-schemes of finite type with finite fibers. Then $\dim Y\leq\dim X$. A morphism $f$ as in (4) is called quasi-finite.