is_living() - determine whether an object is alive or not
This apply is used by the parser to determine whether an object is alive or not, that is to say an NPC or player as opposed to a table. It should return an int 1 for "yes, I'm alive" and 0 for "no, I'm not alive." This response is used to check whether the object is allowed to match a "LIV" rule (see below) or not. The response is cached and so should it change parse_refresh() will need to be called before the will notice.