From: "Alexander E. Gutman" <CyrTeX-ru@vsu.ru>
Received: by relay1.vsu.ru (CommuniGate Pro PIPE 5.2.10)
  with PIPE id 136443477; Thu, 27 Nov 2008 17:09:42 +0300
X-drweb-hash:                      
Received: from mail.math.nsc.ru ([193.125.180.3] verified)
  by relay1.vsu.ru (CommuniGate Pro SMTP 5.2.10)
  with ESMTP id 136435731 for CyrTeX-ru@vsu.ru; Thu, 27 Nov 2008 16:38:42 +0300
Received-SPF: none
 receiver=relay1.vsu.ru; client-ip=193.125.180.3; envelope-from=gutman@math.nsc.ru
Received: from g2m419a.math.nsc.ru (g2m419a.math.nsc.ru [192.168.1.185])
	(authenticated bits=0)
	by ns.math.nsc.ru (8.13.6/8.13.6) with ESMTP id mARDcffb004464
	for <CyrTeX-ru@vsu.ru>; Thu, 27 Nov 2008 19:38:41 +0600 (NOVT)
	(envelope-from gutman@math.nsc.ru)
Date: Thu, 27 Nov 2008 19:38:37 +0600
Reply-To: "Alexander E. Gutman" <gutman@math.nsc.ru>
Organization: Sobolev Institute
X-Priority: 3 (Normal)
Message-ID: <163541855.20081127193837@math.nsc.ru>
To: "Cyrillic TeX Users Group" <CyrTeX-ru@vsu.ru>
Subject: =?koi8-r?B?UmU6INPX0drBzs7ZyiDXxcvUz9I=?=
In-Reply-To: <list-136430353@relay1.vsu.ru>
References: <list-136249312@relay1.vsu.ru> <list-136296950@relay1.vsu.ru> <list-136349890@relay1.vsu.ru> <list-136357169@relay1.vsu.ru> <list-136377943@relay1.vsu.ru> <list-136430353@relay1.vsu.ru>
MIME-Version: 1.0
Content-Type: text/plain; charset=koi8-r
Content-Transfer-Encoding: 8bit
X-DrWeb-FlyTrap-Class: NON-SPAM
X-DrWeb-FlyTrap-CID: 1
X-DrWeb-FlyTrap-ID: 15408550

Здравствуйте, друзья.

Kostin (K) 27.11.2008 (19:01):

K> Хотя может встретиться необходимость напечатать
K> вектор $A_{1}B{1}$ и, к сожалению,
K> стрелка над вектором не становится длиннее.

А вот Вам! :-)

\documentclass[12pt]{article}
\usepackage[cp866]{inputenc}
\usepackage[russian]{babel}

\font\smallcrossfont=cmbsy5 at 3pt
\def\smallcross{\textfont2\smallcrossfont}
\def\cross#1{\raise\fontdimen22#12
  \hbox{\raise.2pt\hbox{$\smallcross\times$}}}

\makeatletter
\def\xlongvec#1{\vbox{\m@th\ialign{##\crcr
  $\cross\scriptfont\mskip-4mu$\rightarrowfill\crcr
  \noalign{\kern-\p@\nointerlineskip}
  $\hfil\displaystyle{\strut#1}\hfil$\crcr}}}
\makeatother

\begin{document}
$\xlongvec{ab}$
$\xlongvec{A_2 B_2 C_3}$
$\xlongvec{a_1 b_2 c_3 d_4 e_5}$
\end{document}

-- 
Александр Гутман