/media/sda-magnetic/david/Dokumente-15-2023-11-22/informatik/compilerbau/pattern-matching/robert-sedgewick/regsave.c

int expression () {
    term ();
    if (p [j] == '+')
        expression();
}
int term () {
    factor ();
    if (( p [j] == '(') || letter (p [j]))
        term ();
}
int factor () {
    if (p [j] == '(') {
        expression ();
        if (p [j] == ')')
            j++;
        else
            error ();
    }
    else if (letter (p [j])) {


    }
    else
        error ();
    if (p [j] != '*')
        ...
    else
    {
    }
}