[Tex/LaTex] Why is \blitza displayed as a psi in beamer

beamersymbols

This is my code:

\documentclass{beamer}

\usepackage{amsmath, amssymb, amsthm}
\usepackage{ulsy}

\begin{document}
    \frame{
        \begin{align*}
            \blitza
        \end{align*}
    }
\end{document}

Why is the \blitza symbol displayed as a psi?

Best Answer

The definition of \blitza in ulsy.sty is

\newcommand{\blitza}{{\usefont{U}{ulsy}{m}{n}\symbol{'011}}}

which clearly means it's a symbol just for text mode.

In math mode \usefont does nothing at all, so what is executed is equivalent to {\symbol{'011}} which is just the same as

{\char'011\relax}

and the rules of TeX say that this will be the symbol in octal position '011 of mathgroup zero font, which is an uppercase Psi.

You can use it in math mode if you redefine it with \text:

\renewcommand{\blitza}{\text{\usefont{U}{ulsy}{m}{n}\symbol{'011}}}
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