fix tizkcd figure

2021_Algebra_I.tex

@@ -851,14 +851,12 @@ The following will lead to another proof of the Nullstellensatz, which uses the
     \label{artintate}
     Let $A$ be a subalgebra of the $R$-algebra $B$, where $R$ is Noetherian. If $ B / R$ is of finite type and $B / A$ is finite, then $A / R$ is also of finite type.
 
-    \begin{figure}[H]
-        \centering
+      \[
         \begin{tikzcd}
             A \arrow[hookrightarrow]{rr}{\subseteq}& & B  \\
                             &R \arrow{ul}{\alpha} \arrow{ur}{\alpha} \text{~(Noeth.)}
         \end{tikzcd}
-    \end{figure}
-    
+      \]
 \end{proposition}
 \begin{proof}
     Let $(b_i)_{i=1}^{m}$ generate $B$ as an $A$-module and $(\beta_j)_{j=1}^m$ as an $R$-algebra.