Goal:
    a : byte  b : byte  H : NoConfusion_byte a b
  ============================
   (a = b)


DEBUG:Going to execute:
subst *
Level 0: Backtrace:

Failed to progress.
Level 1: Backtrace:

Failed to progress.
Level 0: Backtrace:

Failed to progress.
Level 0: Backtrace:

Failed to progress.