Goal:
  
  A : Type
  P : A → Type
  p : A → bool
  q : A → bool
  x : A
  l : list A
  p0 : P x
  X : All P l
  H : ∀ x : A, P x → p x = q x
  H0 : forallb p l = forallb q l
  ============================
   (p x && forallb p l = q x && forallb q l)


DEBUG:Going to execute:
<Coq.Init.Tauto.is_unit_or_eq> flags X1; Ltac.cut X2;
            [ intro; clear id
            | Ltac.cut X1; [ exact id | constructor 1; fail ] ]
Level 0: Backtrace:

q is used in conclusion.
Level 0: Backtrace:

q is used in conclusion.
Level 0: Backtrace:

q is used in conclusion.
Level 0: Backtrace:

q is used in conclusion.
Level 0: Backtrace:

q is used in conclusion.
Level 1: Backtrace:

q is used in conclusion.
Level 0: Backtrace:

q is used in conclusion.
Level 2: Backtrace:

Not convertible.
Level 2: Backtrace:

Not convertible.
Level 2: Backtrace:

Not convertible.
Level 1: Backtrace:

Not convertible.