simp only [admitsAux] at h1
D : Type
I : Interpretation D
V' : VarAssignment D
P : PredName
zs : List VarName
H : Formula
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V : VarAssignment D) (F : Formula) (binders : Finset VarName),
    admitsAux P zs H binders F →
      (∀ x ∉ binders, V x = V' x) →
        let E_ref := tail✝;
        Holds D (I' D I V' E_ref P zs H) V E_ref F ↔ Holds D I V E_ref (replace P zs H F)
E_ref : Env := head✝ :: tail✝
phi : Formula
phi_ih :
  ∀ (V : VarAssignment D) (binders : Finset VarName),
    admitsAux P zs H binders phi →
      (∀ x ∉ binders, V x = V' x) →
        (Holds D (I' D I V' E_ref P zs H) V E_ref phi ↔ Holds D I V E_ref (replace P zs H phi))
V : VarAssignment D
binders : Finset VarName
h1 : admitsAux P zs H binders phi.not_
h2 : ∀ x ∉ binders, V x = V' x
⊢ Holds D (I' D I V' E_ref P zs H) V E_ref phi.not_ ↔ Holds D I V E_ref (replace P zs H phi.not_)
D : Type
I : Interpretation D
V' : VarAssignment D
P : PredName
zs : List VarName
H : Formula
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V : VarAssignment D) (F : Formula) (binders : Finset VarName),
    admitsAux P zs H binders F →
      (∀ x ∉ binders, V x = V' x) →
        let E_ref := tail✝;
        Holds D (I' D I V' E_ref P zs H) V E_ref F ↔ Holds D I V E_ref (replace P zs H F)
E_ref : Env := head✝ :: tail✝
phi : Formula
phi_ih :
  ∀ (V : VarAssignment D) (binders : Finset VarName),
    admitsAux P zs H binders phi →
      (∀ x ∉ binders, V x = V' x) →
        (Holds D (I' D I V' E_ref P zs H) V E_ref phi ↔ Holds D I V E_ref (replace P zs H phi))
V : VarAssignment D
binders : Finset VarName
h1 : admitsAux P zs H binders phi
h2 : ∀ x ∉ binders, V x = V' x
⊢ Holds D (I' D I V' E_ref P zs H) V E_ref phi.not_ ↔ Holds D I V E_ref (replace P zs H phi.not_)