Goal:
  
  A : Type
  P : A → A → Type
  Q : A → Type
  HPQ : ∀ x y : A, Q x → P x y → Q y
  hd : A
  hd' : A
  tl : list A
  p : P hd hd'
  q : Q hd
  H : All Q tl
  ============================
   (Q ?x)


DEBUG:Going to execute:
solve [ intuition eauto  3 with core terms ]
Level 0: Backtrace:

Tactic failure: Cannot solve this goal.
Level 5: Backtrace:

Tactic failure: Cannot solve this goal.
Level 4: Backtrace:

Tactic failure: Cannot solve this goal.
Level 4: Backtrace:

Tactic failure: Cannot solve this goal.
Level 3: Backtrace:

Tactic failure: Cannot solve this goal.
Level 2: Backtrace:

Tactic failure: Cannot solve this goal.
Level 1: Backtrace:

Tactic failure: Cannot solve this goal.
Level 0: Backtrace:

Tactic failure: Cannot solve this goal.