<check_ce:categorization>Categorizations of models:
- Selected model 0: NC
  - Concrete RAC: FAILURE (assertion at "bench/check-ce/ref2.mlw", line 7, characters 11-16)
  - Abstract RAC: STUCK (failure in postcondition of `(:=)` at "WHY3DATA/stdlib/ref.mlw", line 20, characters 39-44)
- Checked model 1: NC
  - Concrete RAC: FAILURE (assertion at "bench/check-ce/ref2.mlw", line 7, characters 11-16)
  - Abstract RAC: FAILURE (assertion at "bench/check-ce/ref2.mlw", line 7, characters 11-16)
- Checked model 2: NC
  - Concrete RAC: FAILURE (assertion at "bench/check-ce/ref2.mlw", line 7, characters 11-16)
  - Abstract RAC: FAILURE (assertion at "bench/check-ce/ref2.mlw", line 7, characters 11-16)
File "bench/check-ce/ref2.mlw", line 7, characters 11-16:
Sub-goal Assertion of goal f'vc.
Prover result is: Unknown (unknown) (3 steps).
The program does not comply to the verification goal, for example during the
  following execution:
Unknown location:
    _ = ()
File ref2.mlw:
  Line 4:
    _ = ()
    Execution of main function `f` with env:
      _ = ()
  Line 5:
    Normal execution of function `ref` with args:
      contents = 1
    Normal execution of function `ref'mk` with args:
      contents = 1
  Line 6:
    Normal execution of function `(:=)` with args:
      r = {contents= 1}
      v = 2
  Line 7:
    Property failure at assertion with:

