- \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
- }
+ \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
+ }
+ \providecommand{\proofname}{Proof}