simp only [Holds]
D : Type
I : Interpretation D
M : MetaValuation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : Valuation D) (F : Formula) (vs : List VarName),
    NoMetaVarAndAllFreeInList vs F → (∀ v ∈ vs, V v = V' v) → (Holds D I V M tail✝ F ↔ Holds D I V' M tail✝ F)
X : PredName
xs : List VarName
V V' : Valuation D
vs : List VarName
h2 : ∀ v ∈ vs, V v = V' v
h1 : xs ⊆ vs
⊢ Holds D I V M (head✝ :: tail✝) (pred_ X xs) ↔ Holds D I V' M (head✝ :: tail✝) (pred_ X xs)
D : Type
I : Interpretation D
M : MetaValuation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : Valuation D) (F : Formula) (vs : List VarName),
    NoMetaVarAndAllFreeInList vs F → (∀ v ∈ vs, V v = V' v) → (Holds D I V M tail✝ F ↔ Holds D I V' M tail✝ F)
X : PredName
xs : List VarName
V V' : Valuation D
vs : List VarName
h2 : ∀ v ∈ vs, V v = V' v
h1 : xs ⊆ vs
⊢ I X (List.map V xs) ↔ I X (List.map V' xs)