#!/usr/bin/perl -w 
use strict;
use Data::Dumper;
use Data::Dump qw (pp);

my %animals;
my %verbs;

# Your say, "In the example above, the only feat that occurs 
#            both with beast and frog is kill-v". 
#
# I don't see it
# Obviously there is something that I don't understand...
#
# this simple code gets multiple things in common
# I don't understand how to filter out "see-v" and "turn-v"
# Prints:
#    turn-v: beast-n frog-n
#    see-v: beast-n frog-n
#    kill-v: beast-n frog-n

while (<DATA>)
{
   my ($animal, $verb) = (split(' ', $_))[1,3];
   $animals{$animal}++;
   push @{$verbs{$verb}}, $animal;
}

foreach my $verb (keys %verbs)
{
   if (@{$verbs{$verb}} > 1)
   {
      print "$verb: @{$verbs{$verb}}", "\n";
   } 
}

__DATA__
1   beast-n into    transform-v 356.9551
2   beast-n obj kill-v  266.2511
3   beast-n obj see-v   252.3623
4   beast-n prd become-v    250.9534
5   beast-n obj tame-v  224.6948
6   beast-n into    turn-v  191.9883
7   beast-n obj call-v  171.4000
8   beast-n sbj_intr    devour-v    165.3228
9   beast-n obj hunt-v  155.7637
10  beast-n obj fight-v 150.4370
11  beast-n obj slay-v  150.3982
1   frog-n  obj find-v  322.5589
2   frog-n  into    turn-v  307.3012
3   frog-n  sbj_intr    jump-v  235.0503
4   frog-n  coord-1 toad-n  207.3611
5   frog-n  obj see-v   207.2610
6   frog-n  obj eat-v   204.1762
7   frog-n  obj kill-v  64.6689