(deftemplate unit "combat unit for game AI"
  (slot hitpoints (type NUMBER))
  (slot movespeed (type NUMBER))
  (slot name)
  (slot attack)
)

(deftemplate attack "combat weapon for game AI"
  (slot name)
  (slot damage (type NUMBER))
)

(deffacts
  (unit
    (name infantry-1)
    (hitpoints 1)
    (movespeed 3)
    (attack fire-rifle))
  (unit
    (name infantry-2)
    (hitpoints 1)
    (movespeed 3)
    (attack fire-rifle))
  (unit
    (name tank-1)
    (hitpoints 10)
    (movespeed 1)
    (attack fire-20mm))
  (attack
    (name fire-rifle)
    (damage 1))
  (attack
    (name fire-20mm)
    (damage 5))
)

(defrule resolve-attack
  (resolve ?unit1 ?attack ?unit2) ;unit1 does attack to unit2
  (unit (name ?u1) (hitpoints ?h1) (abilities ?attack) (movespeed ?m1))
  (attack (name ?attack) (damage ?d))
  ?uf1 <- (unit (name ?u1) (hitpoints ?h2) (abilities ?attack) (movespeed ?m1))
  =>
  (retract ?uf1)
  (if (< (- ?h2 ?d) 0) then
    (assert ((unit (name ?u1) (hitpoints (- ?h2 ?d)) (abilities ?attack) (movespeed ?m1)))))
)