(VAR x y z fun xs)
(RULES
  app(app(app(f, x), app(c, x)), app(c, y)) -> app(app(app(f, y), y), app(app(app(f, y), x), y))
  app(app(app(f, app(s, x)), y), z) -> app(app(app(f, x), app(s, app(c, y))), app(c, z))
  app(app(app(f, app(c, x)), x), y) -> app(c, y)
  app(app(g, x), y) -> x
  app(app(g, x), y) -> y

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

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

)
(STRATEGY INNERMOST)