Item-Lose-Energy names a function, with lambda list (ITEM AMOUNT):
Decrease the energy of ITEM by AMOUNT (stopping at zero).
If the item's energy reaches zero, the effect of its :On-Zero flag will occur; either it will remain :EMPTY, or :VANISH.
If ITEM's Energy-Kind is :COUNTABLE, then AMOUNT must be an integer.
Defined in file src/items.lisp.