Availability::- use_module(library(persistency)).(can be autoloaded)
 persistent(+Spec)
Declare dynamic database terms. Declarations appear in a directive and have the following format:
:- persistent
        <callable>,
        <callable>,
        ...

Each specification is a callable term, following the conventions of library(record), where each argument is of the form

name:type

Types are defined by library(error).

 persistent(+Spec)
Declare dynamic database terms. Declarations appear in a directive and have the following format:
:- persistent
        <callable>,
        <callable>,
        ...

Each specification is a callable term, following the conventions of library(record), where each argument is of the form

name:type

Types are defined by library(error).