\mathcal doesn't have the usual output

Question

I used these commands in order to have along with the \mathcal{L} a calligraphic L as well

\documentclass[11pt,a4paper]{report}
\usepackage{amsmath,amssymb}
\usepackage{calrsfs}
\DeclareMathAlphabet{\pazocal}{OMS}{zplm}{m}{n}
\newcommand{\La}{\mathcal{L}}
\newcommand{\Lb}{\pazocal{L}}

\begin{document}
$\La \Lb$
\end{document}

but now the other letters with \mathcal are not what they supposed to be. My question is, therefore, how can I keep using the \La,\Lb commands for the two L's and at the same time have the usual output of \mathcal for other letters, take \mathcal{O} for example.

Answer 1

\mathcal is automatically assigned to the reference package calrsfs (I think). If you want the classic \mathcal, you can use \pazocal instead of \mathcal as in the example below.

\documentclass[a4paper,12pt]{article}
\usepackage{amsmath,amssymb}
\usepackage{calrsfs}
\DeclareMathAlphabet{\pazocal}{OMS}{zplm}{m}{n}
\SetMathAlphabet\pazocal{bold}{OMS}{zplm}{bx}{n}
\newcommand{\mth}{\mathcal{A}}
\newcommand{\pzc}{\pazocal{A}}

\begin{document}
$\mathcal{A}$, $\pazocal{A},\boldsymbol{\pazocal{A}}$, $\mth,\pzc$
\end{document}