Formulate correctness of buildCfg using end-to-end traces

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

Language/Properties.agda

@@ -8,7 +8,7 @@ open import Language.Traces
 open import Data.Fin as Fin using (zero)
 open import Data.List using (_∷_; [])
 open import Data.List.Membership.Propositional.Properties as ListMemProp using ()
-open import Data.Product using (Σ; _,_)
+open import Data.Product using (Σ; _,_; _×_)
 open import Data.Vec.Properties using (lookup-++ˡ; ++-identityʳ; lookup-++ʳ)
 open import Relation.Binary.PropositionalEquality as Eq using (_≡_; refl; sym)
 
@@ -81,3 +81,7 @@ Trace-loop : ∀ (g₁ : Graph) {idx₁ idx₂ : Graph.Index g₁} {ρ₁ ρ₂
 Trace-loop g₁ {idx₁} {idx₁} (Trace-single ρ₁⇒ρ₂) = Trace-single ρ₁⇒ρ₂
 Trace-loop g₁ {idx₁} (Trace-edge ρ₁⇒ρ idx₁→idx tr') =
     Trace-edge ρ₁⇒ρ (ListMemProp.∈-++⁺ˡ idx₁→idx) (Trace-loop g₁ tr')
+
+buildCfg-sufficient : ∀ {s : Stmt} {ρ₁ ρ₂ : Env} → ρ₁ , s ⇒ˢ ρ₂ →
+                      EndToEndTrace {buildCfg s} ρ₁ ρ₂
+buildCfg-sufficient = {!!}