lstlistings：lstset 中的符号 morekeywords

Question

由于某种原因，morekeywords 不将=>、<=和check-sat作为以下示例中的关键字。是否有解决方法或更合适的方法来做到这一点？

\documentclass[a4paper,12pt]{article}
\usepackage{listings}

\lstset
{
    numbers             =left,
    numberstyle         =\color{gray},
    keywordstyle        =\bfseries,
    morekeywords        ={
        forall, exists,
        assert, check-sat,
        =>, <=, 
        and, or
    }, 
    breaklines          =true,
    frame               =tlrb
}

\begin{document}
\begin{lstlisting}
(assert(
    forall ((x Int) (y Int) (z Int) (t Int)) 
        (=>
            (and
                (<= 0 (+ y z))
                (<= (+ y z) 1))
            (=>
                (= 1 (+ x t y z))
                (=>
                    (distinct 0 (+ y z))
                    (= 0 (+ x t)))))
))

(check-sat)
\end{lstlisting}
\end{document}

Answer 1

添加\usepackage{listingsutf8}和 \usepackage{lmodern}并将符号添加为字母alsoletters似乎有效

\documentclass[a4paper,12pt]{article}
\usepackage{listings}
\usepackage{listingsutf8}
\usepackage{lmodern}

\lstset
{
    numbers             =left,
    numberstyle         =\color{gray},
    alsoletter          ={<=, =>, +, -, =},
    morekeywords        ={
        forall,exists,
        assert,check-sat,distinct,
        =>, <=, =, +,
        and,or}, 
    keywordstyle        =\bfseries\boldmath,
    breaklines          =true,
    frame               =tlrb
}

\begin{document}
\begin{lstlisting}
(assert(
    forall ((x Int) (y Int) (z Int) (t Int)) 
        (=>
            (and
                (<= 0 (+ y z))
                (<= (+ y z) 1))
            (=>
                (= 1 (+ x t y z))
                (=>
                    (distinct 0 (+ y z))
                    (= 0 (+ x t)))))
))

(check-sat)
\end{lstlisting}
\end{document}