Toc disappears after adding the acronym key

Question

I'm trying to write my own notes.
I had added the listing of acronyms on top of my file, but when I compile my project, for an unknown reason an error pops out of my IDE, and it says: Missing \endcsname inserted. <to be read again>
The line in which it occurs is:
\newacro{$\varepsilon $-NFA}[\AC@hyperlink{$\varepsilon $-NFA}{$\varepsilon $-NFA}]{Epsilon NFA}
And the tex code is this:\

document.tex [that is an input for my main file]

\newpage
\vspace*{\fill}
{\centering Questa pagina è stata intenzionalmente lasciata in bianco\par}
\vspace{\fill}
\newpage
\tableofcontents
\newpage
\input{tex/Legenda}
\input{tex/Lezione1}

Legenda.tex

Legenda:
\begin{acronym}[VBLAST]  % longest acronym to fix width
    \acro{f(tran)}{Funzione di Transizione}\acused{f(tran)}
    \acro{DFA}{Automa a Stati Finiti Deterministico}\acused{DFA}
    \acro{NFA}{Automa a Stati Finiti Non Deterministico}
    \acro{$\eps$-NFA}{Epsilon NFA}
\end{acronym}
\newpage

Basically in my index page at the beginning, the toc seems to disappear, even if the pdf file is "correctly" generated.
I also tried to include Legenda in the toc, but the result is the same.
Thanks in advance

Answer 1

The first parameter of \acro must be simple ASCII characters, or something that expands to that (in TeX terms, it must expand to character tokens). If you have anything else, you should choose a name that complies and put the real stuff in an optional argument, like:

\acro{eps-NFA}[$\varepsilon$-NFA]{Epsilon NFA}