Symbols instead of foonotes numbers

Question

I have already seen such questions here, but I need a different solution here. Could someone please explain me, how can I change numbers of my footnotes to the multiple symbols, e.g. *, **,*** etc. without creating errors and chaos in the .tex code?

Thank you!

\documentclass{article}
\usepackage{amsfonts}
\begin{document}
\begin{itemize}
\item Hello, I am the first sentence!\footnote{Ummh.. Looks good with a text!}
\item $\forall n \in \mathbb{N} \ \exists m: n=2m\footnote{I am the second footnote, and not a $m^2$ expression.} \lor n=2m+1$
\end{itemize}
\end{document}

Answer 1

The typical symbol-like style of \footnotes are defined in the LaTeX kernel in the following way:

\def\@fnsymbol#1{%
   \ifcase#1\or \TextOrMath\textasteriskcentered *\or
   \TextOrMath \textdagger \dagger\or
   \TextOrMath \textdaggerdbl \ddagger \or
   \TextOrMath \textsection  \mathsection\or
   \TextOrMath \textparagraph \mathparagraph\or
   \TextOrMath \textbardbl \|\or
   \TextOrMath {\textasteriskcentered\textasteriskcentered}{**}\or
   \TextOrMath {\textdagger\textdagger}{\dagger\dagger}\or
   \TextOrMath {\textdaggerdbl\textdaggerdbl}{\ddagger\ddagger}\else
   \@ctrerr \fi
}%

When printing the footnote number, it conditions on the value of the counter using \ifcase, and each possible outcome is listed in the sequential order of the counter.

We can follow the same approach using *s:

\documentclass{article}

\renewcommand{\thefootnote}{\ifcase\value{footnote}
  \or *% 1
  \or **% 2
  \or ***% 3
  \or ****% 4
  \or *****% 5
  \or ******% 6
  \or *******% 7
  \or ********% 8
  \or *********% 9
  \else \arabic{footnote}\fi}

\begin{document}

\begin{itemize}
  \item First item\footnote{First footnote}
  \item Second item\footnote{Second footnote}
  \item Third item\footnote{Third footnote}
  \item Fourth item\footnote{Fourth footnote}
  \item Fifth item\footnote{Fifth footnote}
  \item Sixth item\footnote{Sixth footnote}
  \item Seventh item\footnote{Seventh footnote}
  \item Eighth item\footnote{Eighth footnote}
  \item Ninth item\footnote{Ninth footnote}
  \item Last item\footnote{Last footnote}
\end{itemize}

\end{document}

It does get a bit unwieldy for large footnote numbers, as the asterisks butt into the margin.

Answer 2

I guess you want to use the footmisc package so the footnote “numbers” are reset at each page. Here I define a maximum of four footnotes for a page, using more will raise an error.

\documentclass{article}
\usepackage[a6paper]{geometry} % just for getting small pictures
\usepackage[perpage,symbol*]{footmisc}
\usepackage{amssymb}

\DefineFNsymbols*{asterisks}{{*}{**}{***}{****}}
\setfnsymbol{asterisks}

\begin{document}
\begin{itemize}
\item Hello, I am the first sentence!\footnote{Ummh.. Looks good with a text!}
\item $\forall n \in \mathbb{N}$ $\exists m: n=2m\footnote{I am the second
  footnote, and not a $m^2$ expression.} \lor n=2m+1$
\end{itemize}
\newpage
\begin{itemize}
\item Hello, I am the first sentence!\footnote{Ummh.. Looks good with a text!}
\item $\forall n \in \mathbb{N}$ $\exists m: n=2m\footnote{I am the second
  footnote, and not a $m^2$ expression.} \lor n=2m+1$
\end{itemize}
\end{document}

The usage of geometry is just to make small pictures for showing the output.

Side note. When you seem to need \<space> in a math formula, ask yourself if you actually have two formulas, like in this case. And, please, don't inflict footnotes in math mode to your readers: they're very ambiguous.