Goal:
  
  A : Type
  P : list A → A → Type
  Q : list A → list A → A → A → Type
  d' : A
  Γ'0 : list A
  d : A
  Γ : list A
  X : All_fold P Γ
  p : P Γ d
  IHX : ∀ Γ' : list A,
          All2_fold Q Γ Γ'
          → All2_fold (λ (Γ Γ'0 : list A) (d d' : A), P Γ d × Q Γ Γ'0 d d') Γ
              Γ'
  H : All2_fold Q Γ Γ'0
  q : Q Γ Γ'0 d d'
  ============================
   (let H := CoreTactics.block in
    let H0 := CoreTactics.block in
    All2_fold (λ (Γ Γ' : list A) (d d' : A), P Γ d × Q Γ Γ' d d') 
      (d :: Γ) (d' :: Γ'0))


DEBUG:Going to execute:
fail 1

Goals:
    A : Type  P : list A → A → Type  Q : list A → list A → A → A → Type
  ============================
   (let H := CoreTactics.block in
    let H0 := CoreTactics.block in
    All2_fold (λ (Γ Γ' : list A) (d d' : A), P Γ d × Q Γ Γ' d d') [] [])

  
  A : Type
  P : list A → A → Type
  Q : list A → list A → A → A → Type
  d' : A
  Γ'0 : list A
  d : A
  Γ : list A
  X : All_fold P Γ
  p : P Γ d
  IHX : ∀ Γ' : list A,
          All2_fold Q Γ Γ'
          → All2_fold (λ (Γ Γ'0 : list A) (d d' : A), P Γ d × Q Γ Γ'0 d d') Γ
              Γ'
  H : All2_fold Q Γ Γ'0
  q : Q Γ Γ'0 d d'
  ============================
   (let H := CoreTactics.block in
    let H0 := CoreTactics.block in
    All2_fold (λ (Γ Γ' : list A) (d d' : A), P Γ d × Q Γ Γ' d d') 
      (d :: Γ) (d' :: Γ'0))


DEBUG:Going to execute:
DepElim.simplify_IH_hyps
Level 2: Backtrace:

Tactic failure (level 1).
Level 1: Backtrace:

Tactic failure.
Level 0: Backtrace:

Tactic failure.

Goals:
    A : Type  P : list A → A → Type  Q : list A → list A → A → A → Type
  ============================
   (let H := CoreTactics.block in
    let H0 := CoreTactics.block in
    All2_fold (λ (Γ Γ' : list A) (d d' : A), P Γ d × Q Γ Γ' d d') [] [])

  
  A : Type
  P : list A → A → Type
  Q : list A → list A → A → A → Type
  d' : A
  Γ'0 : list A
  d : A
  Γ : list A
  X : All_fold P Γ
  p : P Γ d
  IHX : ∀ Γ' : list A,
          All2_fold Q Γ Γ'
          → All2_fold (λ (Γ Γ'0 : list A) (d d' : A), P Γ d × Q Γ Γ'0 d d') Γ
              Γ'
  H : All2_fold Q Γ Γ'0
  q : Q Γ Γ'0 d d'
  ============================
   (let H := CoreTactics.block in
    let H0 := CoreTactics.block in
    All2_fold (λ (Γ Γ' : list A) (d d' : A), P Γ d × Q Γ Γ' d d') 
      (d :: Γ) (d' :: Γ'0))


DEBUG:Going to execute:
repeat
            match goal with
            | hyp:context [ CoreTactics.block ]
              |- _ =>
                  cbn beta in hyp; eqns_specialize_eqs_block hyp;
                   cbn[eq_rect_r eq_rect] in hyp
            end