%components = %component_id_tag;

    $anon_id = 0;
    while (($id, $component) = each(%components)) {
	$component =~ s/\#//g;
	($type, $name) = split (/:/, $component);
	if (! $name) {
	    $component = "${component}:mtt${component}_${anon_id}";
	}
	$anon_id++;
	$components{$id} = $component;
    }

    output_ibg_header();

	    $head = $start;
	    $tail = $end;
	}

	$start_label = $bond_id_start_label{$dia_bond_id};
	$end_label   = $bond_id_end_label  {$dia_bond_id};

	# treat label as a comment if not enclosed by [ ]
	if ($start_label !~  /\[.*\]/) {
	    $start_label = "[]";
	}
	if ($end_label !~ /\[.*\]/) {
	    $end_label = "[]";
	}

	# ignore label if it is not enclosed by []
#	$start_label =~ s/[^[]*\[\([^]]*\)\]/[$1]/;
#	$end_label   =~ s/[^[]*\[\([^]]*\)\]/[$1]/;

	if ($bond_id_arrow_on_start{$dia_bond_id}) {
	    $head_label = $end_label;
	    $tail_label = $start_label;
	} else {
	    $head_label = $start_label;
	    $tail_label = $end_label;

    my ($type, $attribute_node, $new_value )= @_;
    my ($subnode);
    $subnode = get_first_subnode_by_nodename_attribute(0,$attribute_node,$type);

    $subnode->setAttribute(val => $new_value);
#    return $subnode->getAttributeNode("val")->getValue;
}

sub get_dia_attribute_string {
    my ($attribute) = @_;
    my ($str_elem, $string);
    $str_elem = get_first_element_subnode($attribute);
    $string = get_first_text_subnode($str_elem)->getData;
    $string =~ s/\#//g;
    return $string;
}

sub get_arrow_info {
    my ( $object_node, $id, $id_index )= @_;
    my($attribute,$attributes);

    $attribute = get_first_subnode_by_nodename_attribute(1,$object_node, "dia:attribute", "name", "arrow_on_start");
    $bond_id_arrow_on_start{$id} = defined($attribute) ? get_dia_attribute_value("dia:boolean",$attribute) : 0;

    $attribute = get_first_subnode_by_nodename_attribute(1,$object_node, "dia:attribute", "name", "effort_causality");
    change_causality($id_index, $attribute, $change_effort_causality);
    $bond_id_effort_causality{$id} = defined($attribute) ? get_dia_attribute_value("dia:enum",$attribute)-1 : 1;

    $attribute = get_first_subnode_by_nodename_attribute(1,$object_node, "dia:attribute", "name", "flow_causality");
    change_causality($id_index, $attribute, $change_flow_causality);
    $bond_id_flow_causality{$id} = defined($attribute) ? get_dia_attribute_value("dia:enum",$attribute)-1 : 1;

    $attribute = get_first_subnode_by_nodename_attribute(1,$object_node, "dia:attribute", "name", "start_label");
    $bond_id_start_label{$id} = defined($attribute) ? get_dia_attribute_string($attribute) : "[]";


    $attribute = get_first_subnode_by_nodename_attribute(1,$object_node, "dia:attribute", "name", "end_label");
    $bond_id_end_label{$id} = defined($attribute) ? get_dia_attribute_string($attribute) : "[]";


}

sub change_causality() {
    my ($id_index, $attribute_node, $causality_change_string)=@_;
    my ($mtt_id, $arrow_oriented_causality);

    foreach my $id_causality (split(/;/,$causality_change_string)) {