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local variable(+Name, ?Init)

Creates the untyped non-logical variable Name.
An atom.
Any term


A non-logical variable with name Name (visible only in the caller module) is created. Its value is initialised to Init. The contents of the variable persists across failures. The value of a non-logical variable can be changed with setval/2 and retrieved with getval/2. Setting and retrieving terms from a non-logical variable involves copying the term each time. In particular, if the term contains variables, they lose their identity and are replaced with fresh ones.


Declaring a variable twice is silently accepted, and the second declaration is ignored.

Modes and Determinism


(4) instantiation fault
Name is not instantiated.
(5) type error
Name is not an atom.


      :- local variable(a,[]).
      :- local variable(count,0), variable(value,colour(red)).

      :- local variable(X, []).                      (Error 4).
      :- local variable(6, 0).                       (Error 5).

See Also

current_array / 2, array / 1, array / 2, decval / 1, incval / 1, bag_create / 1, getval / 2, setval / 2, reference / 2, variable / 1