sub in_list {my $target=shift; return 0+grep { $_ eq $target } @_} 

##</code><code>##

sub in_list {my $target=shift; $_ eq $target and return 1 for @_; return} 

##</code><code>##

sub find_first_index {
  my $target=shift;
  push @_,$target;
  my $i=0;
  $i++ while $_[$i] ne $target;
  return $i==$#_ ? undef : $i
}