[Haskell-cafe] adjoint of coproduct & diagonal

Jason Dusek jason.dusek at gmail.com
Sun Aug 3 14:03:03 EDT 2008

  What about the part that reads:

    The unique arrow f making this diagram commute is then
    correspondingly denoted f1 ∐ f2 or f1 ⊕ f2 or f1 + f2 or
    [f1, f2]

  This would seem to say that [f,g] and f+g are the same thing
  -- but if I've understood Derek Elkins' remarks, the latter is
  the functorial action on arrows while the former is just the
  mediating arrow.


More information about the Haskell-Cafe mailing list