From e7f40eed8a5a43139ee78fa0e1c4dd04299ee94f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Frederik=20Hangh=C3=B8j=20Iversen?= <fhi.1990@gmail.com>
Date: Tue, 22 May 2018 15:35:21 +0200
Subject: [PATCH] Scaffolding for proving groupoid for monads

---
 src/Cat/Category/Monad/Kleisli.agda | 33 ++++++++++++++++++++++++++++-
 src/Cat/Prelude.agda                |  6 +++---
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/src/Cat/Category/Monad/Kleisli.agda b/src/Cat/Category/Monad/Kleisli.agda
index 366886b..6cc8cae 100644
--- a/src/Cat/Category/Monad/Kleisli.agda
+++ b/src/Cat/Category/Monad/Kleisli.agda
@@ -1,7 +1,7 @@
 {---
 The Kleisli formulation of monads
  ---}
-{-# OPTIONS --cubical #-}
+{-# OPTIONS --cubical --allow-unsolved-metas #-}
 open import Agda.Primitive
 
 open import Cat.Prelude
@@ -265,3 +265,34 @@ module _ {m n : Monad} (eq : Monad.raw m ≡ Monad.raw n) where
   Monad≡ : m ≡ n
   Monad.raw     (Monad≡ i) = eq i
   Monad.isMonad (Monad≡ i) = eqIsMonad i
+
+module _ where
+  private
+    module _ (x y : RawMonad) (p q : x ≡ y) (a b : p ≡ q) where
+      eq0-helper : isGrpd (Object → Object)
+      eq0-helper = grpdPi (λ a → ℂ.groupoidObject)
+
+      eq0 : cong (cong RawMonad.omap) a ≡ cong (cong RawMonad.omap) b
+      eq0 = eq0-helper
+        (RawMonad.omap x)             (RawMonad.omap y)
+        (cong RawMonad.omap p)        (cong RawMonad.omap q)
+        (cong (cong RawMonad.omap) a) (cong (cong RawMonad.omap) b)
+
+      eq1-helper : (omap : Object → Object) → isGrpd ({X : Object}   → ℂ [ X , omap X ])
+      eq1-helper f = grpdPiImpl (setGrpd ℂ.arrowsAreSets)
+
+      postulate
+        eq1 : PathP (λ i → PathP
+          (λ j →
+          PathP (λ k → {X : Object} → ℂ [ X , eq0 i j k X ])
+          (RawMonad.pure x) (RawMonad.pure y))
+          (λ i → RawMonad.pure (p i)) (λ i → RawMonad.pure (q i)))
+          (cong-d (cong-d RawMonad.pure) a) (cong-d (cong-d RawMonad.pure) b)
+
+    grpdRaw : isGrpd RawMonad
+    RawMonad.omap (grpdRaw x y p q a b x₁ x₂ x₃) = eq0 x y p q a b x₁ x₂ x₃
+    RawMonad.pure (grpdRaw x y p q a b x₁ x₂ x₃) = {!eq1 x y p q a b x₁ x₂ x₃!}
+    RawMonad.bind (grpdRaw x y p q a b x₁ x₂ x₃) = {!!}
+
+  -- grpdKleisli : isGrpd Monad
+  -- grpdKleisli = {!!}
diff --git a/src/Cat/Prelude.agda b/src/Cat/Prelude.agda
index 2f0a8f2..62dd5bd 100644
--- a/src/Cat/Prelude.agda
+++ b/src/Cat/Prelude.agda
@@ -107,13 +107,13 @@ module _ {ℓ : Level} {A : Set ℓ} where
   ntypeCumulative {m}         ≤′-refl      lvl = lvl
   ntypeCumulative {n} {suc m} (≤′-step le) lvl = HasLevel+1 ⟨ m ⟩₋₂ (ntypeCumulative le lvl)
 
-  grpdPi : {ℓa ℓb : Level} {A : Set ℓa} {B : A → Set ℓb}
+  grpdPi : {ℓb : Level} {B : A → Set ℓb}
     → ((a : A) → isGrpd (B a)) → isGrpd ((a : A) → (B a))
   grpdPi = piPresNType (S (S (S ⟨-2⟩)))
 
-  grpdPiImpl : {ℓa ℓb : Level} {A : Set ℓa} {B : A → Set ℓb}
+  grpdPiImpl : {ℓb : Level} {B : A → Set ℓb}
     → ({a : A} → isGrpd (B a)) → isGrpd ({a : A} → (B a))
-  grpdPiImpl {A = A} {B} g = equivPreservesNType {A = Expl} {B = Impl} {n = one} e (grpdPi (λ a → g))
+  grpdPiImpl {B = B} g = equivPreservesNType {A = Expl} {B = Impl} {n = one} e (grpdPi (λ a → g))
     where
     one = (S (S (S ⟨-2⟩)))
     t : ({a : A} → HasLevel one (B a))