Goal:
    A : Type  d : A  v : A  H : d = v
  ============================
   (None = None ∧ v = d)


DEBUG:Going to execute:
solve [ split; do_ccl ]
Level 1: Backtrace:

Failed to progress.
Level 0: Backtrace:

Failed to progress.
Level 0: Backtrace:

Failed to progress.
Level 0: Backtrace:

Failed to progress.
Level 0: Backtrace:

Failed to progress.