< patent-list6.final.classgen \
 gawk -F\; '{
printf "%s", $1 ":"
for (i=2; i<=NF; i++) {
  split($i,s,"/");
  if (dup[s[1]]!=$1) printf "%s", s[1] ":"
  dup[s[1]]=$1;
}
printf "\n"
}'
