%  vc.tex    Vektor-Halbpfeil   
%            ( \vc , \pvc , \ppvc and \vctil ) 

\documentclass[12pt]{article} \pagestyle{empty}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%  packages
\usepackage{amssymb} \usepackage{ifthen} 

%  widetilde : \schl
\def\schl#1{\ifthenelse{\equal{#1}{i}}{\widetilde{\imath}}{
\ifthenelse{\equal{#1}{j}}{\widetilde{\jmath}}{\widetilde{#1}} } } 

%  equations
\def\be#1{\begin{equation} \label{#1}}  \def\ee{\end{equation}}
\def\bea#1{\begin{eqnarray} \label{#1}}  \def\eea{\end{eqnarray}} 

%  greek
   \let\a=\alpha   \let\b=\beta   \let\d=\delta  \let\g=\gamma
   \let\l=\lambda  \let\o=\omega  \let\s=\sigma  \let\z=\zeta
   \let\e=\varepsilon  \let\ph=\varphi   \let\ta=\vartheta
   \let\vrho=\varrho   \let\D=\Delta     \let\G=\Gamma  
   \let\L=\Lambda      \let\O=\Omega     \let\Y=\Upsilon

%  dotted vectors : \pvc , \ppvc
  \def\pvc#1{{\buildrel {_{\hbox{\,\bf .}}} \over {{\vc #1}}}}
  \def\ppvc#1{{\buildrel {_{\hbox{\,\bf ..}}} \over {{\vc #1}}}}

%  vectors : \vc
\def\pueb#1#2{\hspace*{-#1mm}{\buildrel{\hspace*{#1mm}
  \hspace*{#1mm} _\rightharpoonup}\over{#2}}\hspace*{-#1mm}
  \hspace*{-#1mm}\hspace*{-.2mm}}
\def\gpueb#1#2{\hspace*{-#1mm}\hspace*{.4mm}{\buildrel{
  \hspace*{#1mm}\hspace*{#1mm}{\displaystyle _\rightharpoonup}}
  \over{#2}}\hspace*{-#1mm}\hspace*{-#1mm}\hspace*{.4mm}}
\def\vc#1{
  \ifthenelse{\equal{#1}{f} \or \equal{#1}{d}}{\pueb{.4}{#1}}{
  \ifthenelse{\equal{#1}{e} \or \equal{#1}{k} \or \equal{#1}{l} 
    \or \equal{#1}{r} \or \equal{#1}{s} \or \equal{#1}{t} 
    \or \equal{#1}{\b} \or \equal{#1}{\beta} \or \equal{#1}{\ell} 
    \or \equal{#1}{\phi} \or \equal{#1}{\vrho} 
    \or \equal{#1}{\varrho}}{\pueb{.2}{#1}}{   
  \ifthenelse{\equal{#1}{j}}{\pueb{.4}{\jmath}}{
  \ifthenelse{\equal{#1}{i}}{\pueb{.4}{\imath}}{
  \ifthenelse{\equal{#1}{m} \or \equal{#1}{w} \or \equal{#1}{\o}
       \or \equal{#1}{\omega}}{\gpueb{0}{#1}}{
  \ifthenelse{\equal{#1}{A} \or \equal{#1}{R}}{\gpueb{.2}{#1}}{
  \ifthenelse{\equal{#1}{B} \or \equal{#1}{C} \or \equal{#1}{D} 
 \or \equal{#1}{E} \or \equal{#1}{F} \or \equal{#1}{G} \or \equal{#1}{H} 
 \or \equal{#1}{I} \or \equal{#1}{J} \or \equal{#1}{K} \or \equal{#1}{L} 
 \or \equal{#1}{M} \or \equal{#1}{N} \or \equal{#1}{O} \or \equal{#1}{P} 
 \or \equal{#1}{Q} \or \equal{#1}{S} \or \equal{#1}{T} \or \equal{#1}{U} 
 \or \equal{#1}{V} \or \equal{#1}{W} \or \equal{#1}{X} \or \equal{#1}{Y} 
 \or \equal{#1}{Z}}{\gpueb{.4}{#1}}{\pueb{0}{#1}}} }}} }} }

%  vector over widetilde : \vctil
%    wer den folgenden (recht unwichtigen) Teil loescht, kann den 
%    Halbpfeil auch bequem per \vc {\widetilde{x}} ueber tilde-x 
%    bekommen und gegebenenfalls per   U\vc {V\widetilde{Yx}Z  
%    an den Stellen U,V,Y,Z Rechts- bzw. Linksrueckungen einfuegen.
\def\vueb#1#2{\hspace*{-#1mm}{\buildrel{\hspace*{#1mm}
  \hspace*{#1mm} _\rightharpoonup}\over{\schl #2}}
  \hspace*{-#1mm}\hspace*{-.2mm}}
\def\gvueb#1#2{\hspace*{.3mm}\hspace*{-#1mm}{\buildrel{\hspace*{#1mm}
  \hspace*{#1mm} {\displaystyle _\rightharpoonup}}\over{\schl #2}}
  \hspace*{-#1mm}}
\def\vctil#1{
  \ifthenelse{\equal{#1}{f} \or \equal{#1}{d}}{\vueb{.6}{#1}}{
  \ifthenelse{\equal{#1}{e} \or \equal{#1}{k} \or \equal{#1}{l} 
     \or \equal{#1}{r} \or \equal{#1}{s} \or \equal{#1}{t} 
     \or \equal{#1}{\b}  \or \equal{#1}{\beta} \or \equal{#1}{\ell} 
     \or \equal{#1}{\phi} \or \equal{#1}{\vrho}\or \equal{#1}{\varrho} 
     \or \equal{#1}{\ta}  \or \equal{#1}{\vartheta}}{\vueb{.2}{#1}}{   
  \ifthenelse{\equal{#1}{A} \or \equal{#1}{R}}{\gvueb{.6}{#1}}{
  \ifthenelse{\equal{#1}{m} \or \equal{#1}{w} \or \equal{#1}{\o}
     \or \equal{#1}{\omega} \or \equal{#1}{B} \or \equal{#1}{C} 
     \or \equal{#1}{D}  \or \equal{#1}{E} \or \equal{#1}{F} 
     \or \equal{#1}{G} \or \equal{#1}{H}  \or \equal{#1}{I} 
     \or \equal{#1}{J} \or \equal{#1}{K} \or \equal{#1}{L} 
     \or \equal{#1}{M} \or \equal{#1}{N} \or \equal{#1}{O} 
     \or \equal{#1}{P} \or \equal{#1}{Q} \or \equal{#1}{S} 
     \or \equal{#1}{T} \or \equal{#1}{U} \or \equal{#1}{V} 
     \or \equal{#1}{W} \or \equal{#1}{X} \or \equal{#1}{Y} 
     \or \equal{#1}{Z}}{\gvueb{.4}{#1}}{\vueb{0}{#1} }}}} }
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

\begin{document}

\centerline{{\large\bf Vektorhalbpfeile 
             \quad $\backslash$vc} {\rm \{ \}} ,} 
\centerline{welche sorgloses Index-Anh\"angen vertragen, 
sowie $\backslash$pvc , $\backslash$ppvc , $\backslash$vctil .} 

\vskip 1cm
\be{1}
  \vc a \quad \vc b_0 \quad \vc e_1 \quad \vc d \quad 
  \vc f_2 \quad \vc \ell \quad \vc m \quad \vc p \quad 
  \vc r_3 \quad \vc \o  \quad \vc i \quad \vc j
\ee 
\be{2}
  \pvc a \quad \pvc b \quad \pvc e \quad \pvc d \quad 
  \pvc f_1 \quad \pvc \ell \quad \pvc m \quad \pvc p \quad 
  \pvc r \quad \pvc \o  \quad \pvc i \quad \pvc j
\ee 
\be{3}
  \ppvc a \quad \ppvc b \quad \ppvc e \quad \ppvc d \quad 
  \ppvc f \quad \ppvc \ell \quad \ppvc m \quad \ppvc p \quad 
  \ppvc r \quad \ppvc \o  \quad \ppvc i \quad \ppvc j
\ee 
\be{4}
  \vctil a \quad \vctil b \quad \vctil e \quad \vctil d \quad 
  \vctil f \quad \vctil \ell \quad \vctil m \quad \vctil p \quad 
  \vctil r \quad \vctil \o   \quad \vctil i \quad \vctil j 
  \quad \vctil \ta
\ee 

\be{5}
  \vc A \quad \vc R \quad \vc B \quad \vc E \quad 
  \vc I \quad \vc M \quad \vc U 
\ee 
\be{6}
  \pvc A \quad \pvc R \quad \pvc B \quad \pvc E \quad 
  \pvc I \quad \pvc M \quad \pvc U 
\ee 
\be{7}
  \ppvc A \quad \ppvc R \quad \ppvc B \quad \ppvc E \quad 
  \ppvc I \quad \ppvc M \quad \ppvc U 
\ee 
\be{8}
  \vctil A \quad \vctil R \quad \vctil B_0 \quad \vctil E \quad 
  \vctil I \quad \vctil M \quad \vctil U \quad 
\ee

\vskip .4cm \noindent
\"Uber ''unerwartete'' Objekte, wie z.B. griechische 
Gro\ss buchstaben, setzt $\backslash$vc automatisch den etwas
k\"urzeren Pfeil (jenen f\"ur Kleinbuchstaben), und zwar ohne
etwaige Rechtsr\"uckung: 
\be{9}
  \vc \Gamma \quad  \vctil \Gamma \quad \vc \Delta \quad 
  \vc \Box \quad  \vc = \quad  \vctil = \quad  \vc \sum \quad  
  \vctil \bigcirc \quad \vc \int \quad \vctil \int
\ee

\vskip 3cm \noindent
Der file hierzu hei\ss t vc.tex, ben\"otigt kein makro und
steht als source file jedermann zur Verf\"ugung. Es w\"are
doch sch\"on, wenn sich das, was man schreibt, auch beim 
Herrn LATEX durchsetzen w\"urde. 23.~9.~99, H.S.
  
\end{document}




