Fixed the following warning:

  (\end occurred inside a group at level 1)
  ### simple group (level 1) entered at line 99 ({)
  ### bottom level

fithesis3/style/mu/base.dtx

@@ -140,16 +140,13 @@
 % subsequently loaded style files to test for either the
 % \Hologo{XeTeX} or \Hologo{LuaTeX} engline being used.
 %    \begin{macrocode}
-\def\thesis@ifxeluatex{{%
-  \let\x\expandafter\let\f\csname\let\t\endcsname
-  \ifxetex\x\f\x i\x f\x t\x r\x u\x e\x\t
-  \else
-    \ifluatex\x\x\x\f\x\x\x i\x\x\x f\x\x\x t\x\x\x r%
-             \x\x\x u\x\x\x e\x\x\x\t
-    \else    \x\x\x\f\x\x\x i\x\x\x f\x\x\x f\x\x\x a%
-             \x\x\x l\x\x\x s\x\x\x e\x\x\x\t
+{\let\x\expandafter
+\x\global\x\let\x\thesis@ifxeluatex\csname if%
+  \ifxetex true\else
+    \ifluatex\x\x\x t\x\x\x r\x\x\x u\x\x\x e%
+    \else   f\x\x\x a\x\x\x l\x\x\x s\x\x\x e%
     \fi
-  \fi}}
+  \fi\endcsname}
 %    \end{macrocode}
 % The following packages get only loaded, when the document is
 % being typeset using the \Hologo{XeTeX} or \Hologo{LuaTeX}