[ HasLightSource i j ad;
    if (i == 0) rfalse;
    if (i has light) rtrue;
    if (i has enterable || IsSeeThrough(i) == 1)
        if (~~(HidesLightSource(i)))
            objectloop (j in i)
                if (HasLightSource(j) == 1) rtrue;
    ad = i.&add_to_scope;
    if (parent(i) ~= 0 && ad ~= 0) {
        if (metaclass(ad-->0) == Routine) {
            ats_hls = 0; ats_flag = 1;
            RunRoutines(i, add_to_scope);
            ats_flag = 0; if (ats_hls == 1) rtrue;
        }
        else {
            for (j=0 : (WORDSIZE*j)<i.#add_to_scope : j++)
                if (HasLightSource(ad-->j) == 1) rtrue;
        }
    }
    rfalse;
];