### 8.5 FD variable information

- `fd_min/2`, `fd_max/2`, `fd_size/2`, `fd_dom/2`
- `fd_has_extra_cstr/1`, `fd_has_vector/1`, `fd_use_vector/1`

These predicate allow the user to get some information about FD variables. They are not constraints, they only return the current state of a variable.

#### 8.5.1 `fd_min/2`, `fd_max/2`, `fd_size/2`, `fd_dom/2`

Templates

  `fd_min(+fd_variable, ?integer)
  fd_max(+fd_variable, ?integer)
  fd_size(+fd_variable, ?integer)
  fd_dom(+fd_variable, ?integer_list)`

Description

`fd_min(X, N)` succeeds if `N` is the minimal value of the current domain of `X`.

`fd_max(X, N)` succeeds if `N` is the maximal value of the current domain of `X`.

`fd_size(X, N)` succeeds if `N` is the number of elements of the current domain of `X`.

`fd_dom(X, Values)` succeeds if `Values` is the list of values of the current domain of `X`.

Errors

`X` is a variable |  | `instantiation_error`
`X` is neither an FD variable nor an integer |  | `type_error(fd_variable, X)`
`N` is neither a variable nor an integer |  | `type_error(integer, N)`
an element `E` of the `Vars` list is neither a variable nor an FD variable nor an integer |  | `type_error(fd_variable, E)`
`Values` is neither a partial list nor a list |  | `type_error(list, Values)`

Portability

GNU Prolog predicate.

#### 8.5.2 `fd_has_extra_cstr/1`, `fd_has_vector/1`, `fd_use_vector/1`

Templates

  `fd_has_extra_cstr(+fd_variable)
  fd_has_vector(+fd_variable)
  fd_use_vector(+fd_variable)`

Description

`fd_has_extra_cstr(X)` succeeds if the `extra_cstr` of `X` is currently on (section 8.1).

`fd_has_vector(X)` succeeds if the current domain of `X` uses a sparse representation (section 8.1).

`fd_use_vector(X)` enforces a sparse representation for the domain of `X` (section 8.1).

Errors

`X` is a variable |  | `instantiation_error`
`X` is neither an FD variable nor an integer |  | `type_error(fd_variable, X)`

Portability

GNU Prolog predicates.

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