sub P {
# This is so that we don't go off the deep end with recursion : )
   return [1,1] if $_[0]==1&&$_[1]==1;
   return [1] if $_[0]==1;

# If there's only one argument, return a list of lists containing
# the argument and it's partitions.
   if (@_==1) {
      return [@_], P($_[0]-1,1)

# Otherwise return a list of lists containing the arguments and
# the partitions of the opposites.
   } else {
      return [@_],
         map({ [@$_, $_[1]] } P($_[0])),
         map({ [$_[0], @$_] } P($_[1]))
   }
}