Switch maps (and consequently most of the code) to using instances

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

Lattice/MapSet.agda

@@ -1,8 +1,9 @@
 open import Lattice
 open import Relation.Binary.PropositionalEquality as Eq using (_≡_; refl; sym; trans; cong; subst)
 open import Agda.Primitive using (Level) renaming (_⊔_ to _⊔ℓ_)
+open import Data.Unit using (⊤)
 
-module Lattice.MapSet {a : Level} {A : Set a} (≡-Decidable-A : IsDecidable (_≡_ {a} {A})) where
+module Lattice.MapSet {a : Level} (A : Set a) {{≡-Decidable-A : IsDecidable (_≡_ {a} {A})}} (dummy : ⊤) where
 
 open import Data.List using (List; map)
 open import Data.Product using (_,_; proj₁)
@@ -11,7 +12,7 @@ open import Function using (_∘_)
 open import Lattice.Unit using (⊤; tt) renaming (_≈_ to _≈₂_; _⊔_ to _⊔₂_; _⊓_ to _⊓₂_; isLattice to ⊤-isLattice)
 import Lattice.Map
 
-private module UnitMap = Lattice.Map ≡-Decidable-A ⊤-isLattice
+private module UnitMap = Lattice.Map A ⊤ dummy
 open UnitMap
     using (Map; Expr; ⟦_⟧)
     renaming