Remove mentionings of DOS.
diff --git a/Doc/tut/tut.tex b/Doc/tut/tut.tex
index 512dd6e..41d7e33 100644
--- a/Doc/tut/tut.tex
+++ b/Doc/tut/tut.tex
@@ -176,7 +176,7 @@
\file{/usr/local/python} is a popular alternative location.)
Typing an end-of-file character (\kbd{Control-D} on \UNIX,
-\kbd{Control-Z} on DOS or Windows) at the primary prompt causes the
+\kbd{Control-Z} on Windows) at the primary prompt causes the
interpreter to exit with a zero exit status. If that doesn't work,
you can exit the interpreter by typing the following commands:
\samp{import sys; sys.exit()}.