Goal:
  
  A : Type
  B : Type
  R : A → B → Prop
  x : A
  y : list B
  a1' : list A
  a1 : list B
  a : Forall2 R a1' a1
  ============================
   ({| pr1 := [x]; pr2 := y |} = {| pr1 := a1'; pr2 := a1 |}
    → let H := CoreTactics.block in
      let H0 := CoreTactics.block in ∃ y' : B, y = [y'] ∧ R x y')


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
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1


Level 3: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1

Level 2: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1


Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1

Level 2: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1

Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1

Level 1: evaluation
raised the exception
Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1


Level 1: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1

Level 0: Backtrace:


Could not find an instance for "DepElim.DependentEliminationPackage
                                  (Forall2 R a1' a1)"
in
environment:
A : Type
B : Type
R : A → B → Prop
x : A
y : list B
a1' : list A
a1 : list B
a : Forall2 R a1' a1