Add missing edge

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

Language.agda

@@ -38,6 +38,8 @@ data BasicStmt : Set where
     noop : BasicStmt
 
 infixr 2 _then_
+infix 3 while_repeat_
+infix 3 if_then_else_
 data Stmt : Set where
     ⟨_⟩ : BasicStmt → Stmt
     _then_ : Stmt → Stmt → Stmt
@@ -350,7 +352,7 @@ module Graphs where
         buildCfg (while _ repeat s) =
             (buildCfg s ⟨⊗⟩ pushEmptyBlock ⟨⊗⟩ pushEmptyBlock)
             update (λ { g ((idx₁ , idx₂) , idx , idx') →
-                      addEdges g ((idx , idx') ∷ (idx₂ , idx) ∷ []) })
+                      addEdges g ((idx , idx') ∷ (idx , idx₁) ∷ (idx₂ , idx) ∷ []) })
             map (λ { g ((idx₁ , idx₂) , idx , idx') → (idx , idx') })
 
 open import Lattice.MapSet _≟ˢ_