7.11 AMS Encodings

<..ams 2000 art + book + proc..>+
 \def\:tempc#1#2#3#4#5{%
   \expandafter\ifx \csname #1mathaccentV\endcsname\relax
      \o:mathaccentV:{#1}{#2}{#3}{#4}{#5}%
   \else  \csname #1mathaccentV\endcsname{#5}\fi}
 \HLet\mathaccentV\:tempc
 \:CheckOption{new-accents}     \if:Option \else
    <.ams 2000 iso-8859-1 accents.>
 \fi
 \def\:temp{charset=iso-8859-2}
 \ifx \a:charset\:UnDef
       \ifx  \A:charset\:temp \let\:temp=\def \fi
 \else \ifx  \a:charset\:temp \let\:temp=\def \fi
 \fi
 \ifx \:temp\def
    \:CheckOption{new-accents}     \if:Option \else
       <.old ams 2000 iso-8859-2 accents.>
 \fi \fi
-_-_-

<..ams 2000 iso-8859-1 accents..>
 \HRestore\grave
 \expandafter\let\csname gravemathaccentV\endcsname=\grave
 \expandafter\let\csname GRAVEmathaccentV\endcsname=\grave
 \expand:after{\Configure{accent}}\csname
            gravemathaccentV\expandafter\endcsname
    \csname GRAVEmathaccentV\endcsname{<.grave codes.>{}{}}
    {\a:accents{grave}{#1}}   {\b:accents{grave}{#1}{#2}}
 \HRestore\acute
 \expandafter\let\csname acutemathaccentV\endcsname=\acute
 \expandafter\let\csname ACUTEmathaccentV\endcsname=\acute
 \expand:after{\Configure{accent}}\csname
            acutemathaccentV\expandafter\endcsname
    \csname ACUTEmathaccentV\endcsname{<.acute codes.>{}{}}
    {\a:accents{acute}{#1}}   {\b:accents{acute}{#1}{#2}}
 \HRestore\hat
 \expandafter\let\csname hatmathaccentV\endcsname=\hat
 \expandafter\let\csname HATmathaccentV\endcsname=\hat
 \expand:after{\Configure{accent}}\csname
            hatmathaccentV\expandafter\endcsname
    \csname HATmathaccentV\endcsname{<.hat iso-8859-1.>{}{}}
    {\a:accents{hat}{#1}}   {\b:accents{hat}{#1}{#2}}
 \HRestore\tilde
 \expandafter\let\csname tildemathaccentV\endcsname=\tilde
 \expandafter\let\csname TILDEmathaccentV\endcsname=\tilde
 \expand:after{\Configure{accent}}\csname
            tildemathaccentV\expandafter\endcsname
    \csname TILDEmathaccentV\endcsname{<.tilde codes.>{}{}}
    {\a:accents{tilde}{#1}}   {\b:accents{tilde}{#1}{#2}}
 \HRestore\ddot
 \expandafter\let\csname DDOTmathaccentV\endcsname=\ddot
 \expand:after{\Configure{accent}}\csname
            DDOTmathaccentV\expandafter\endcsname
    \csname DDOTmathaccentV\endcsname{<.ddot iso-8859-1.>{}{}}
    {\a:accents{ddot}{#1}}   {\b:accents{ddot}{#1}{#2}}
 \expandafter\let\csname ddotmathaccentV\endcsname=\ddot
 \expand:after{\Configure{accent}}\csname
            ddotmathaccentV\expandafter\endcsname
    \csname ddotmathaccentv\endcsname{<.ddot iso-8859-1.>{}{}}
    {\a:accents{ddot}{#1}}   {\b:accents{ddot}{#1}{#2}}
 \HRestore\check
 \expandafter\let\csname checkmathaccentV\endcsname=\check
 \expandafter\let\csname CHECKmathaccentV\endcsname=\check
 \expand:after{\Configure{accent}}\csname
            checkmathaccentV\expandafter\endcsname
    \csname CHECKmathaccentV\endcsname{<.caron codes.>{}{}}
    {\a:accents{check}{#1}}   {\b:accents{check}{#1}{#2}}
 \HRestore\dot
 \expandafter\let\csname dotmathaccentV\endcsname=\dot
 \expandafter\let\csname DOTmathaccentV\endcsname=\dot
 \expand:after{\Configure{accent}}\csname
            dotmathaccentV\expandafter\endcsname
    \csname DOTmathaccentV\endcsname{<.dot above codes.>{}{}}
    {\a:accents{dot}{#1}}   {\b:accents{dot}{#1}{#2}}
 \HRestore\breve
 \expandafter\let\csname brevemathaccentV\endcsname=\breve
 \expandafter\let\csname BREVEmathaccentV\endcsname=\breve
 \expand:after{\Configure{accent}}\csname
            brevemathaccentV\expandafter\endcsname
    \csname BREVEmathaccentV\endcsname{<.breve codes.>{}{}}
    {\a:accents{breve}{#1}}   {\b:accents{breve}{#1}{#2}}
 \HRestore\bar
 \expandafter\let\csname barmathaccentV\endcsname=\bar
 \expandafter\let\csname BARmathaccentV\endcsname=\bar
 \expand:after{\Configure{accent}}\csname
            barmathaccentV\expandafter\endcsname
    \csname BARmathaccentV\endcsname{<.macron codes.>{}{}}
    {\a:accents{bar}{#1}}   {\b:accents{bar}{#1}{#2}}
 \HRestore\vec
 \expandafter\let\csname vecmathaccentV\endcsname=\vec
 \expandafter\let\csname VECmathaccentV\endcsname=\vec
 \expand:after{\Configure{accent}}\csname
            vecmathaccentV\expandafter\endcsname
    \csname VECmathaccentV\endcsname{<.vec iso-8859-1.>{}{}}
    {\a:accents{vec}{#1}}   {\b:accents{vec}{#1}{#2}}
-_-_-

<..old ams 2000 iso-8859-2 accents..>
 \HRestore\acute
 \expandafter\let\csname acutemathaccentV\endcsname=\acute
 \expandafter\let\csname ACUTEmathaccentV\endcsname=\acute
 \expand:after{\Configure{accent}}\csname
            acutemathaccentV\expandafter\endcsname
    \csname ACUTEmathaccentV\endcsname{<.acute codes.>{}{}}
    {\a:accents{acute}{#1}}   {\b:accents{acute}{#1}{#2}}
-_-_-

The upper case is needed for cases like

\documentclass[12pt]{amsart}  
\begin{document}  
\title{BUDOWA J’’ADER ATOM{O}W PIERWIASTK{O}W}  
\author{Rafa’’l ‘‘Raba--P{o}’’lg’’l{o}wek\’o$\acute{o}$}  
\def\datename{Wersja z}  
\date{\today}  
\maketitle  
\end{document}