# Foo.pm
package Foo;
use Exporter;
@ISA = 'Exporter';
@EXPORT = qw(Foo);
use strict;
sub Foo { Bar("Called from Foo"); }
1;


# Bar.pm
package Bar;
use Exporter;
@ISA = 'Exporter';
@EXPORT = qw(Bar);
use strict;
sub Bar { print "$_[0]\n"; }
1;