!  The CantSee routine returns a good error number for the situation where
!  the last word looked at didn't seem to refer to any object in context.
!
!  The idea is that: if the actor is in a location (but not inside something
!  like, for instance, a tank which is in that location) then an attempt to
!  refer to one of the words listed as meaningful-but-irrelevant there
!  will cause "you don't need to refer to that in this game" rather than
!  "no such thing" or "what's 'it'?".
!  (The advantage of not having looked at "irrelevant" local nouns until now
!  is that it stops them from clogging up the ambiguity-resolving process.
!  Thus game objects always triumph over scenery.)
! ----------------------------------------------------------------------------

[ CantSee  i w e;
    saved_oops=oops_from;

    if (scope_token~=0) { scope_error = scope_token; return ASKSCOPE_PE; }

    wn--; w=NextWord();
    e=CANTSEE_PE;
    if (w==pronoun_word)
    {   pronoun__word=pronoun_word; pronoun__obj=pronoun_obj;
        e=ITGONE_PE;
    }
    i=actor; while (parent(i) ~= 0) i = parent(i);
    if (i has visited && Refers(i,wn-1)==1) e=SCENERY_PE;
    if (etype>e) return etype;
    return e;
];