When a module-file is loaded by load_files/[1,2] or
one of its shorthands (see Read In), by default all the public
predicates of the module-file are imported by the
receiving module. An explicit list of predicates to
import may also be specified.
Name clashes with already existing predicates, local or
imported from other modules, are handled in two different
ways: If the receiving module is the user module, the
user is asked for redefinition of the predicate. For other
receiving modules, a warning is issued and the importation
is canceled. In the first case redefinition silently takes place if the
flag redefine_warnings has the value off (see
prolog_flag/3). The binding of an imported predicate
remains, even if the origin is reloaded or deleted. However,
abolish/[1,2] break up the importation binding. When a
module-file is reloaded, a check is made that the predicates
imported by other modules are still in the public list. If
that is not the case, a warning is issued. Note that an imported
predicate may be re-exported.