# Commit 2021-07-13 18:51 461130bc

View on Github →feat(category_theory/monoidal): the definition of Tor (#7512)

# Tor, the left-derived functor of tensor product

We define `tor C n : C ⥤ C ⥤ C`

, by left-deriving in the second factor of `(X, Y) ↦ X ⊗ Y`

.
For now we have almost nothing to say about it!
It would be good to show that this is naturally isomorphic to the functor obtained
by left-deriving in the first factor, instead.