make sure the document size is set at the right time

vladak · vladak · commit 2cffd7366f9e · 2023-10-02T23:13:45.000+02:00
fixes #51
diff --git a/unix-linux-prog-in-c.tex b/unix-linux-prog-in-c.tex
@@ -5,7 +5,7 @@
 % These are slides with notes.
 %
 
-\AtBeginDocument{%
+\AtBeginDocument[seminar]{%
   \pdfhorigin=1sp
   \pdfvorigin=1sp
   \paperwidth=297truemm
