induction F generalizing F' binders V V'
case cons
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
V V' : VarAssignment D
F F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders F F'
⊢ Holds D I V (head✝ :: tail✝) F ↔ Holds D I V' (head✝ :: tail✝) F'
case cons.pred_const_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ : PredName
a✝ : List VarName
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (pred_const_ a✝¹ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (pred_const_ a✝¹ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.pred_var_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ : PredName
a✝ : List VarName
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (pred_var_ a✝¹ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (pred_var_ a✝¹ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.eq_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ a✝ : VarName
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (eq_ a✝¹ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (eq_ a✝¹ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.true_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders true_ F'
⊢ Holds D I V (head✝ :: tail✝) true_ ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.false_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders false_ F'
⊢ Holds D I V (head✝ :: tail✝) false_ ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.not_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝ : Formula
a_ih✝ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝ F' → (Holds D I V (head✝ :: tail✝) a✝ ↔ Holds D I V' (head✝ :: tail✝) F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders a✝.not_ F'
⊢ Holds D I V (head✝ :: tail✝) a✝.not_ ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.imp_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ a✝ : Formula
a_ih✝¹ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝¹ F' → (Holds D I V (head✝ :: tail✝) a✝¹ ↔ Holds D I V' (head✝ :: tail✝) F')
a_ih✝ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝ F' → (Holds D I V (head✝ :: tail✝) a✝ ↔ Holds D I V' (head✝ :: tail✝) F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (a✝¹.imp_ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (a✝¹.imp_ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.and_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ a✝ : Formula
a_ih✝¹ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝¹ F' → (Holds D I V (head✝ :: tail✝) a✝¹ ↔ Holds D I V' (head✝ :: tail✝) F')
a_ih✝ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝ F' → (Holds D I V (head✝ :: tail✝) a✝ ↔ Holds D I V' (head✝ :: tail✝) F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (a✝¹.and_ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (a✝¹.and_ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.or_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ a✝ : Formula
a_ih✝¹ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝¹ F' → (Holds D I V (head✝ :: tail✝) a✝¹ ↔ Holds D I V' (head✝ :: tail✝) F')
a_ih✝ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝ F' → (Holds D I V (head✝ :: tail✝) a✝ ↔ Holds D I V' (head✝ :: tail✝) F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (a✝¹.or_ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (a✝¹.or_ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.iff_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ a✝ : Formula
a_ih✝¹ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝¹ F' → (Holds D I V (head✝ :: tail✝) a✝¹ ↔ Holds D I V' (head✝ :: tail✝) F')
a_ih✝ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝ F' → (Holds D I V (head✝ :: tail✝) a✝ ↔ Holds D I V' (head✝ :: tail✝) F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (a✝¹.iff_ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (a✝¹.iff_ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.forall_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ : VarName
a✝ : Formula
a_ih✝ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝ F' → (Holds D I V (head✝ :: tail✝) a✝ ↔ Holds D I V' (head✝ :: tail✝) F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (forall_ a✝¹ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (forall_ a✝¹ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.exists_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ : VarName
a✝ : Formula
a_ih✝ :
  ∀ (V V' : VarAssignment D) (F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' →
      isAlphaEqvAux binders a✝ F' → (Holds D I V (head✝ :: tail✝) a✝ ↔ Holds D I V' (head✝ :: tail✝) F')
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (exists_ a✝¹ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (exists_ a✝¹ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'

case cons.def_
D : Type
I : Interpretation D
head✝ : Definition
tail✝ : List Definition
tail_ih✝ :
  ∀ (V V' : VarAssignment D) (F F' : Formula) (binders : List (VarName × VarName)),
    AlphaEqvVarAssignment D binders V V' → isAlphaEqvAux binders F F' → (Holds D I V tail✝ F ↔ Holds D I V' tail✝ F')
a✝¹ : DefName
a✝ : List VarName
V V' : VarAssignment D
F' : Formula
binders : List (VarName × VarName)
h1 : AlphaEqvVarAssignment D binders V V'
h2 : isAlphaEqvAux binders (def_ a✝¹ a✝) F'
⊢ Holds D I V (head✝ :: tail✝) (def_ a✝¹ a✝) ↔ Holds D I V' (head✝ :: tail✝) F'