#! /usr/local/bin/perl -w

use strict;

sub inner {
    print "  inner: $_\n" for @_;
}

sub outer {
    print "outer: $_\n" for @_;
        inner;
        print "\n";
}

sub outer_amp {
    print "outer_amp: $_\n" for @_;
        &inner;
        print "\n";
}

outer( qw/ vroon gukguk faba / );

outer_amp( qw/ foomp tweedle zachitty / );

__RESULTS__

outer: vroon
outer: gukguk
outer: faba

outer_amp: foomp
outer_amp: tweedle
outer_amp: zachitty
  inner: foomp
  inner: tweedle
  inner: zachitty