Theorem 41.13.1. Let $\varphi : X \to Y$ be a morphism of schemes. Let $x \in X$. If $\varphi $ is smooth at $x$, then there exist an integer $n \geq 0$ and affine opens $V \subset Y$ and $U \subset X$ with $x \in U$ and $\varphi (U) \subset V$ such that there exists a commutative diagram
\[ \xymatrix{ X \ar[d] & U \ar[l] \ar[d] \ar[r]_-\pi & \mathbf{A}^ n_ R \ar[d] \ar@{=}[r] & \mathop{\mathrm{Spec}}(R[x_1, \ldots , x_ n]) \ar[dl] \\ Y & V \ar[l] \ar@{=}[r] & \mathop{\mathrm{Spec}}(R) } \]
where $\pi $ is étale.
Comments (2)
Comment #3240 by Dario Weißmann on
Comment #3339 by Johan on