potion_tuple_at   887 core/potion.h  PN potion_tuple_at(Potion *, PN, PN, PN);
potion_tuple_at   837 core/table.c     potion_type_call_is(tpl_vt, PN_FUNC(potion_tuple_at, "index=N"));
potion_tuple_at   840 core/table.c     potion_method(tpl_vt, "at", potion_tuple_at, "index=N");