-extern bool hates_acid(object_type *o_ptr);
-extern bool hates_elec(object_type *o_ptr);
-extern bool hates_fire(object_type *o_ptr);
-extern bool hates_cold(object_type *o_ptr);
-extern int set_acid_destroy(object_type *o_ptr);
-extern int set_elec_destroy(object_type *o_ptr);
-extern int set_fire_destroy(object_type *o_ptr);
-extern int set_cold_destroy(object_type *o_ptr);
-extern int inven_damage(inven_func typ, int perc);
-extern int acid_dam(HIT_POINT dam, cptr kb_str, int monspell, bool aura);
-extern int elec_dam(HIT_POINT dam, cptr kb_str, int monspell, bool aura);
-extern int fire_dam(HIT_POINT dam, cptr kb_str, int monspell, bool aura);
-extern int cold_dam(HIT_POINT dam, cptr kb_str, int monspell, bool aura);