Goal:
  
  A : Type
  B : Type
  R : A → B → Type
  l : list A
  a : B
  r1 : list B
  r2 : list B
  h1' : list A
  h1 : list B
  h : All2 R h1' h1
  ============================
   ({| pr1 := l; pr2 := a :: r1 ++ r2 |} = {| pr1 := h1'; pr2 := h1 |}
    → let H := CoreTactics.block in
      (∀ (l : list A) (r2 : list B),
         All2 R l (r1 ++ r2)
         → ∑ l1 l2 : list A, l = l1 ++ l2 × All2 R l1 r1 × All2 R l2 r2)
      → let H0 := CoreTactics.block in
        ∑ l1 l2 : list A, l = l1 ++ l2 × All2 R l1 (a :: r1) × All2 R l2 r2)


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 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1


Level 3: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1

Level 2: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1


Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1

Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1

Level 1: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1


Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1

Level 0: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (All2 R h1' h1)"
in
environment:
A : Type
B : Type
R : A → B → Type
l : list A
a : B
r1, r2 : list B
h1' : list A
h1 : list B
h : All2 R h1' h1