for my $i (1..$POLYGONS_MAX_Y) {
    if ( $ET[$i] ) {
        print "ET[$i] = ";
        for my $list ( ${ET[$i]} ) {
            for my $r ( @{$list} ) {
                print "{" . $r->{Ymax} . "|" . 
                            $r->{Xbot} . "|" . 
                            $r->{invSlope} . 
                      "}" ;
            }
        }
        print "\n";
    } else {
        print "ET[$i] = NULL\n";
    }
}