Goal:
    A : Type  P : A → Type  Q : A → Type  Hl' : All Q []
  ============================
   (All (λ x : A, P x × Q x) [])


DEBUG:Going to execute:
intro_block_id H || intro_block H
Level 0: Backtrace:

No quantified hypothesis named Hl' in current goal even after head-reduction.
Level 0: Backtrace:

No quantified hypothesis named Hl' in current goal even after head-reduction.