Type a regular mathcal letter while using newtxmath with the libertine option

libertinemathcalnewtxmath

I am required to use a .cls that loads the newtxmath package with the libertine option. Because of this (I think), when I type \mathcal{A} my "A" looks different than it normally does. I need to typeset a single normal, non-libertine, old-school \mathcal{A}. A once-off, inline solution that works in a math environment would be ideal. Thanks!

Best Answer

The original \mathcal alphabet is from the cmsy font. You can switch to that inside a \text command from amsmath.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage[type1]{libertine}
\usepackage[libertine]{newtxmath}
\usepackage{bm}

\newcommand\varcal[1]{\text{\usefont{OMS}{cmsy}{m}{n}#1}}
\newcommand\varcalA{\varcal{A}}

\begin{document}
\[ A \mathcal{A} \varcal{A} \varcalA
\]
\end{document}

Newtx + Libertine + Computer Modern sample

You could also declare \varcal with \DeclareMathAlphabet, which would have the advantage of working with \boldmath. However, you say you don’t need this, and there is a limit on how many math alphabets legacy 8-bit TeX can use.

If you only need two different script alphabets, you could load one as \mathcal and the other as \mathscr using mathalpha.

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