my $string = '';
$string .= add_one(); $string .= " ";
$string .= add_number(50); $string .= " ";
$string .= subtract_one(); $string .= " ";
$string .= subtract_number(45); $string .= " ";
$string .= value();
check_success ( $string eq "1 51 50 5 5", "This is a comment" );
return ( $string );