### 9.4 Type testing

- `fd_var/1`, `non_fd_var/1`, `generic_var/1`, `non_generic_var/1`

#### 9.4.1 `fd_var/1`, `non_fd_var/1`, `generic_var/1`, `non_generic_var/1`

Templates

  `fd_var(?term)
  non_fd_var(?term)
  generic_var(?term)
  non_generic_var(?term)`

Description

`fd_var(Term)` succeeds if `Term` is currently an FD variable.

`non_fd_var(Term)` succeeds if `Term` is currently not an FD variable (opposite of `fd_var/1`).

`generic_var(Term)` succeeds if `Term` is either a Prolog variable or an FD variable.

`non_generic_var(Term)` succeeds if `Term` is neither a Prolog variable nor an FD variable (opposite of `generic_var/1`).

Errors

None.

Portability

GNU Prolog predicate.

Copyright (C) 1999-2011 Daniel Diaz Verbatim copying and distribution of this entire article is permitted in any medium, provided this notice is preserved. More about the copyright