(VAR x y f xs)
(RULES
  app(p, 0) -> 0
  app(p, app(s, x)) -> x
  app(app(le, 0), y) -> true
  app(app(le, app(s, x)), 0) -> false
  app(app(le, app(s, x)), app(s, y)) -> app(app(le, x), y)
  app(app(minus, x), y) -> app(app(app(if, app(app(le, x), y)), x), y)
  app(app(app(if, true), x), y) -> 0
  app(app(app(if, false), x), y) -> app(s, app(app(minus, app(p, x)), y))

  app(app(map,f),nil) -> nil
  app(app(map,f),app(app(cons,x),xs)) -> app(app(cons,app(f,x)),app(app(map,f),xs))

  app(app(filter,f),nil) -> nil
  app(app(filter,f),app(app(cons,x),xs)) -> app(app(app(app(filter2,app(f, x)),f),x),xs)
  app(app(app(app(filter2,true),f),x),xs) -> app(app(cons,x),app(app(filter,f),xs))
  app(app(app(app(filter2,false),f),x),xs) -> app(app(filter,f),xs)

)
(STRATEGY INNERMOST)