Digits after ^ and _ macros (were: LaTeX restriction?)

Question

In LaTeX, I ran into an annoying problem. I have a tex file of about 1000 lines. I already have a few numbers, but when I try to add another shape, it delays:

! Undefined control sequence.
<argument> ... \sf@size \z@ \selectfont \@currbox

l.937 \begin{figure}[t]

If you move the shape to other parts of the file, I can get similar errors on different lines:

! Undefined control sequence.
<argument> ... \sf@size \z@ \selectfont \@currbox

l.657 \paragraph
                {A Centering Algorithm}

If I comment on the figure, everything is in order.

%\begin{figure}[t]
% \caption{Example decision tree, from Reiter and Dale [2000]}
% \label{fig:relation-decision-tree}
% \centering
% \includegraphics[keepaspectratio=true]{./relation-decision-tree.eps}
%\end{figure}

If I continue only the beginning and the end, for example:

\begin{figure}%[t]
% \caption{Example decision tree, from Reiter and Dale [2000]}
% \label{fig:relation-decision-tree}
% \centering
% \includegraphics[keepaspectratio=true]{./relation-decision-tree.eps}
\end{figure}

I get:

! Undefined control sequence.
<argument> ... \sf@size \z@ \selectfont \@currbox

l.942 \end
          {figure}

At first I thought that maybe LaTeX hit some limit, and I tried to play with ulimits, but that did not help. Any ideas?

I already have other drawings with graphics. my preamble looks like this:

\documentclass[acmcsur,acmnow]{acmtrans2n}
\usepackage{array}
\usepackage{lastpage}
\usepackage{pict2e}
\usepackage{amsmath}
\usepackage{varioref}
\usepackage{epsfig}
\usepackage{graphics}
\usepackage{qtree}
\usepackage{rotating}
\usepackage{tree-dvips}
\usepackage{mdwlist}
\makecompactlist{quote*}{quote}
\usepackage{verbatim}
\usepackage{ulem}

Answer 1

, \textsuperscript, a ^ def http://anthony.liekens.net/index.php/LaTeX/SubscriptAndSuperscriptInTextMode, , ^ {}, , ^ _ {}. !

Answer 2

, . , , - , , \usepackage {pxfonts} \usepackage {txfonts}. , .. ..;)

Answer 3

Google " undefined ", this.

LaTeX, - :

\usepackage{amsmath,amsthm,graphicx}

...

I just wanted to test adding an image to a \LaTeX file:

\includegraphics[scale=0.60]{basic-info.png} 

200 LaTeX . , .

Answer 4

. , , . \documentclass{article} , . , ACM (ROTFLMAO, ACM).

, , \tracingall , , http://pastebin.com/, .

Answer 5

Please receive thanks from a (previously) completely incompatible graduate student. Quick clarification for other users:

{The fastest method {} to apply this solution is to copy all sections of the text with the symbol `` \ ^ '', as shown here.}