- \ifx\proof\undefined\
- \newenvironment{proof}[1][\protect\proofname]{\par
- \normalfont\topsep6\p@\@plus6\p@\relax
- \trivlist
- \itemindent\parindent
- \item[\hskip\labelsep
- \scshape
-#1]\ignorespaces
-}{%
- \endtrivlist\@endpefalse
-}
+ \ifcsname proof\endcsname\else
+ \DeclareRobustCommand{\lyx@qed}{%
+ \ifmmode
+ \else \leavevmode\unskip\penalty9999 \hbox{}\nobreak\hfill
+ \fi
+ \quad\hbox{\lyx@qedsymbol}}
+ \newcommand{\lyx@openbox}{\leavevmode
+ \hbox to.77778em{%
+ \hfil\vrule
+ \vbox to.675em{\hrule width.6em\vfil\hrule}%
+ \vrule\hfil}}
+ \newcommand{\lyx@qedsymbol}{\lyx@openbox}
+ \newenvironment{proof}[1][\proofname]{\par
+ \normalfont
+ \topsep6\p@\@plus6\p@ \trivlist
+ \item[\hskip\labelsep\itshape
+ #1.]\ignorespaces
+ }{%
+ \lyx@qed\endtrivlist
+ }