Goal:
  
  A : Type
  P : list A → A → Type
  Q : list A → list A → A → A → Type
  Δ : list A
  hlen : #|[]| = #|Δ|
  hb : All_fold P Δ
  ============================
   (let H := CoreTactics.block in
    (∀ (Δ Δ' : list A) (x y : A),
       All_fold P Δ
       → All_fold P Δ' → All2_fold Q Δ Δ' → P Δ x → P Δ' y → Q Δ Δ' x y)
    → let H0 := CoreTactics.block in All2_fold Q [] Δ)


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
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ


Level 3: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ

Level 2: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ


Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ

Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ

Level 1: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ


Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ

Level 0: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All_fold P Δ)"
in
environment:
A : Type
P : list A → A → Type
Q : list A → list A → A → A → Type
Δ : list A
hlen : #|[]| = #|Δ|
hb : All_fold P Δ