Add names to schemes because these names are used later

Thanks to Janos Kollar
https://stacks.math.columbia.edu/tag/0EXC#comment-5254

flat.tex

@@ -11457,8 +11457,8 @@ \section{Almost blow up squares and the h topology}
 Then
 $$
 \xymatrix{
-\Spec(A/fA + J) \ar[r] \ar[d] & \Spec(A/J) \ar[d] \\
-\Spec(A/fA) \ar[r] & \Spec(A)
+E = \Spec(A/fA + J) \ar[r] \ar[d] & \Spec(A/J) = X' \ar[d] \\
+Z = \Spec(A/fA) \ar[r] & \Spec(A) = X
 }
 $$
 is an almost blowup square.
@@ -11469,9 +11469,9 @@ \section{Almost blow up squares and the h topology}
 Let $A$ be a ring. Let $f_1, f_2 \in A$ be elements.
 $$
 \xymatrix{
-\text{Proj}(A/(f_1, f_2)[T_0, T_1]) \ar[r] \ar[d] &
-\text{Proj}(A[T_0, T_1]/(f_2 T_0 - f_1 T_1) \ar[d] \\
-\Spec(A/(f_1, f_2)) \ar[r] & \Spec(A)
+E = \text{Proj}(A/(f_1, f_2)[T_0, T_1]) \ar[r] \ar[d] &
+\text{Proj}(A[T_0, T_1]/(f_2 T_0 - f_1 T_1) = X' \ar[d] \\
+Z = \Spec(A/(f_1, f_2)) \ar[r] & \Spec(A) = X
 }
 $$
 is an almost blowup square.