Goal:
  
  A : Type
  P : list A → list A → A → A → Type
  n : nat
  a : A
  Γ : list A
  Γ' : list A
  d : A
  IHn : ∀ (Γ Γ' : list A) (d : A),
          All2_fold P Γ Γ'
          → nth_error Γ n = Some d
            → ∑ d' : A,
                nth_error Γ' n = Some d'
                × (let Γs := skipn (S n) Γ in
                   let Γs' := skipn (S n) Γ' in
                   All2_fold P Γs Γs' × P Γs Γs' d d')
  Hrel1' : list A
  Hrel1 : list A
  Hrel : All2_fold P Hrel1' Hrel1
  ============================
   ({| pr1 := a :: Γ; pr2 := Γ' |} = {| pr1 := Hrel1'; pr2 := Hrel1 |}
    → let H := CoreTactics.block in
      nth_error (a :: Γ) (S n) = Some d
      → let H0 := CoreTactics.block in
        ∑ d' : A,
          nth_error Γ' (S n) = Some d'
          × (let Γs := skipn (S (S n)) (a :: Γ) in
             let Γs' := skipn (S (S n)) Γ' in
             All2_fold P Γs Γs' × P Γs Γs' d d'))


DEBUG:Going to execute:
destruct p || (case p; clear p)
Level 4: evaluation of term
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1


Level 3: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1

Level 2: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1


Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1

Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1

Level 1: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1


Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1

Level 0: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2_fold P Hrel1' Hrel1)"
in
environment:
A : Type
P : list A → list A → A → A → Type
n : nat
a : A
Γ, Γ' : list A
d : A
IHn : ∀ (Γ Γ' : list A) (d : A),
        All2_fold P Γ Γ'
        → nth_error Γ n = Some d
          → ∑ d' : A,
              nth_error Γ' n = Some d'
              × (let Γs := skipn (S n) Γ in
                 let Γs' := skipn (S n) Γ' in
                 All2_fold P Γs Γs' × P Γs Γs' d d')
Hrel1', Hrel1 : list A
Hrel : All2_fold P Hrel1' Hrel1