informoj de la libro.tex

\title{行列式入门}
\author{Determinantulo}
\date{2024} % THE YEAR

% Make aliases for \@title, \@author, \@date.
% Use \let.
\makeatletter
\let\thetitle\@title
\let\theauthor\@author
\let\thedate\@date % THE YEAR
\makeatother