Sometimes, I really love Haskell.

 From the people who gave us such gems as

   "A monad is just a monoid in the category of endofunctors, what's the 
problem?"

and

   "What part of

     x : σ ∈ Γ
     ----------
     Γ ⊢ x : σ


     Γ ⊢ e0 : τ → τ',  Γ ⊢ e1 : τ
     -----------------------------
            Γ ⊢ e0 e1 : τ'


      Γ, x : τ ⊢ e : τ'
     --------------------
     Γ ⊢ λ x . e : τ → τ'


     Γ ⊢ e0 : σ,  Γ, x : σ ⊢ e1 : τ
     -------------------------------
       Γ ⊢ let x = e0 in e1 : τ


     Γ ⊢ e : σ',  σ' ⊑ σ
     --------------------
          Γ ⊢ e : σ


     Γ ⊢ e : σ,  α ∉ free(Γ)
     -------------------------
     Γ ⊢ e : ∀ α . σ

   do you NOT understand?"

today I came across this purified gold dust:

   "Every Cofree Comonad over an Alternative Functor yields a Monad."

My mind, she is blown.

(Whether this is wonderful or appalling depends on your perspective...)

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