Goal:
    A : Type  l : list A  hd : A  tl : list A
  ============================
   (Some hd = Some hd ∧ tl = tl)


DEBUG:Going to execute:
use_hyps; do_ccl
Level 0: Backtrace:

Tactic failure: congruence failed.
Level 0: Backtrace:

Tactic failure: congruence failed.
Level 0: Backtrace:

No applicable tactic.