Let , the free algebra functor

On the free algebra , two notions coincide.

  • A. Based loop space at the origin (co-algebraic Koszul dual). (Aside: observe this is a way to construct the additive structure on the group-stacks Super- (smooth version))
  • B. Functions on free loop space (THH)
    Observe the structure A uses the augmentation, while B does not. So these notions certainly diverge when is replaced by a general ring .