simp only [sub]
D : Type
I : Interpretation D
c : Char
X : DefName
xs : List VarName
V : VarAssignment D
σ : VarName → VarName
⊢ Holds D I V [] (sub σ c (def_ X xs)) ↔ Holds D I (V ∘ σ) [] (def_ X xs)
D : Type
I : Interpretation D
c : Char
X : DefName
xs : List VarName
V : VarAssignment D
σ : VarName → VarName
⊢ Holds D I V [] (def_ X (List.map σ xs)) ↔ Holds D I (V ∘ σ) [] (def_ X xs)