simp only [← substitution_theorem]
c : Char
τ : PredName → ℕ → Option (List VarName × Formula)
F : Formula
h1 : ∀ (D : Type) (I : Interpretation D) (V : VarAssignment D) (E : Env), Holds D I V E F
D : Type
I : Interpretation D
V : VarAssignment D
E : Env
⊢ Holds D I V E (sub c τ F)
c : Char
τ : PredName → ℕ → Option (List VarName × Formula)
F : Formula
h1 : ∀ (D : Type) (I : Interpretation D) (V : VarAssignment D) (E : Env), Holds D I V E F
D : Type
I : Interpretation D
V : VarAssignment D
E : Env
⊢ Holds D (I' D I V E τ) V E F