Goal:
  
  A : Type
  P : nat → A → Type
  p : nat → A → bool
  n : nat
  Hp : ∀ (i : nat) (x : A), reflectT (P i x) (p i x)
  ============================
   (true → Alli P n [])


DEBUG:Going to execute:
<coq-core.plugins.ltac::constructor@0>
Level 0: Backtrace:

No matching clauses for match.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.
Level 1: Backtrace:

No applicable tactic.
Level 0: Backtrace:

No applicable tactic.