$VAR = "old VAR";
    sub func {return ("old func()")}
    sub show {printf "VAR='%s', func()='%s'\n", $VAR, func()}
    
    sub redefine {
        eval 'sub func {return ("new func()")}';
        local ($VAR) = "new VAR";
        show();
    }
    
    show();
    redefine();
    show();