Goal:
  
  A : Type
  B : Type
  P : A → nat → B → Type
  a : A
  ls2 : list A
  n : nat
  X : Alli (λ (n : nat) (y : B), All (λ x : A, P x n y) (a :: ls2)) n []
  ============================
   (All (λ x : A, Alli (P x) n []) ls2)


DEBUG:Going to execute:
H
Level 0: Backtrace:

In environment
A : Type
B : Type
P : A → nat → B → Type
a : A
ls2 : list A
n : nat
X : Alli (λ (n : nat) (y : B), All (λ x : A, P x n y) (a :: ls2)) n []
The term "a" has type "A" while it is expected to have type "All ?P ls2".
Level 0: Backtrace:

In environment
A : Type
B : Type
P : A → nat → B → Type
a : A
ls2 : list A
n : nat
X : Alli (λ (n : nat) (y : B), All (λ x : A, P x n y) (a :: ls2)) n []
The term "a" has type "A" while it is expected to have type "All ?P ls2".
Level 0: Backtrace:

In environment
A : Type
B : Type
P : A → nat → B → Type
a : A
ls2 : list A
n : nat
X : Alli (λ (n : nat) (y : B), All (λ x : A, P x n y) (a :: ls2)) n []
The term "a" has type "A" while it is expected to have type "All ?P ls2".
Level 1: Backtrace:

In environment
A : Type
B : Type
P : A → nat → B → Type
a : A
ls2 : list A
n : nat
X : Alli (λ (n : nat) (y : B), All (λ x : A, P x n y) (a :: ls2)) n []
The term "a" has type "A" while it is expected to have type "All ?P ls2".
Level 2: Backtrace:

In environment
A : Type
B : Type
P : A → nat → B → Type
a : A
ls2 : list A
n : nat
X : Alli (λ (n : nat) (y : B), All (λ x : A, P x n y) (a :: ls2)) n []
The term "a" has type "A" while it is expected to have type "All ?P ls2".