Make 'IsDecidable' into a record to aid instance search

Signed-off-by: Danila Fedorin <danila.fedorin@gmail.com>

Lattice/Map.agda

@@ -1,12 +1,11 @@
 open import Lattice
 open import Relation.Binary.PropositionalEquality as Eq using (_≡_; refl; sym; trans; cong; subst)
-open import Relation.Binary.Definitions using (Decidable)
 open import Agda.Primitive using (Level) renaming (_⊔_ to _⊔ℓ_)
 
 module Lattice.Map {a b : Level} {A : Set a} {B : Set b}
     {_≈₂_ : B → B → Set b}
     {_⊔₂_ : B → B → B} {_⊓₂_ : B → B → B}
-    (≡-dec-A : Decidable (_≡_ {a} {A}))
+    (≡-Decidable-A : IsDecidable {a} {A} _≡_)
     (lB : IsLattice B _≈₂_ _⊔₂_ _⊓₂_) where
 
 open import Data.List.Membership.Propositional as MemProp using () renaming (_∈_ to _∈ˡ_)
@@ -23,6 +22,8 @@ open import Utils using (Unique; push; Unique-append; All¬-¬Any; All-x∈xs)
 open import Data.String using () renaming (_++_ to _++ˢ_)
 open import Showable using (Showable; show)
 
+open IsDecidable ≡-Decidable-A using () renaming (R-dec to ≡-dec-A)
+
 open IsLattice lB using () renaming
     ( ≈-refl to ≈₂-refl; ≈-sym to ≈₂-sym; ≈-trans to ≈₂-trans
     ; ≈-⊔-cong to ≈₂-⊔₂-cong; ≈-⊓-cong to ≈₂-⊓₂-cong
@@ -625,7 +626,8 @@ Expr-Provenance-≡ {k} {v} e k,v∈e
     with (v' , (p , k,v'∈e)) ← Expr-Provenance k e (forget k,v∈e)
     rewrite Map-functional {m = ⟦ e ⟧} k,v∈e k,v'∈e = p
 
-module _ (≈₂-dec : IsDecidable _≈₂_) where
+module _ (≈₂-Decidable : IsDecidable _≈₂_) where
+    open IsDecidable ≈₂-Decidable using () renaming (R-dec to ≈₂-dec)
     private module _ where
         data SubsetInfo (m₁ m₂ : Map) : Set (a ⊔ℓ b) where
             extra : (k : A) → k ∈k m₁ → ¬ k ∈k m₂ → SubsetInfo m₁ m₂
@@ -676,6 +678,9 @@ module _ (≈₂-dec : IsDecidable _≈₂_) where
     ...   | _         | no  m₂̷⊆m₁ = no (λ (_ , m₂⊆m₁) → m₂̷⊆m₁ m₂⊆m₁)
     ...   | no  m₁̷⊆m₂ | _         = no (λ (m₁⊆m₂ , _) → m₁̷⊆m₂ m₁⊆m₂)
 
+    ≈-Decidable : IsDecidable _≈_
+    ≈-Decidable = record { R-dec = ≈-dec }
+
 private module I⊔ = ImplInsert _⊔₂_
 private module I⊓ = ImplInsert _⊓₂_