Warning, file "bench/check-ce/615.mlw", line 2, characters 9-10: unused variable t
<check_ce:categorization>Categorizations of models:
- Selected model 0: NC
  - Concrete RAC: FAILURE (check at "bench/check-ce/615.mlw", line 3, characters 12-28)
  - Abstract RAC: FAILURE (check at "bench/check-ce/615.mlw", line 3, characters 12-28)
- Checked model 1: NC
  - Concrete RAC: FAILURE (check at "bench/check-ce/615.mlw", line 3, characters 12-28)
  - Abstract RAC: FAILURE (check at "bench/check-ce/615.mlw", line 3, characters 12-28)
File "bench/check-ce/615.mlw", line 3, characters 12-28:
Sub-goal Check of goal f'vc.
Prover result is: Unknown (sat) (179 steps).
The program does not comply to the verification goal, for example during the
  following execution:
File int.mlw:
  Line 13:
    Constant zero initialization
    zero = 0
  Line 14:
    Constant one initialization
    one = 1
File 615.mlw:
  Line 2:
    t = 0
    x = 1
    t = 0
    x = 1
    Execution of main function `f` with env:
      t = 0
      x = 1
      zero = 0
      one = 1
  Line 3:
    Property failure at check with:
      x = 1

