6 6 62 9   Exclude diagrams 
 This option can be used to exclude diagrams with virtual
particles named by the user. Examples:
1) Z>2 (excludes diagrams with more than 2 virtual Z-bosons.)
2) Z<2 (excludes diagrams with less than 2 virtual Z-bosons.)
3) Z=2 (excludes diagrams with 2 virtual Z-bosons.)
4) Z!2 (keeps diagrams with only 2 virtual Z-bosons.)
5) Z   (excludes all diagrams with Z-bosons.)

  Use empty input to get the full set of diagrams.