Goal:
    A : Type  P : A → Type  a : A  X : All P [a]
  ============================
   (P a)


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

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

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