my @aOfA=();
for ( my $i=0; $i<=$#nlist; $i++ ) {
    my @tmp = ();
    ( $i > 0 ) and (($nlist[$i] - $nlist[$i-1]) < 2 )
      and $tmp[0]=$nlist[$i-1];
    push @tmp, $nlist[$i];
    ( $i < $#nlist ) and (($nlist[$i+1] - $nlist[$i]) < 2 )
      and push @tmp, $nlist[$i+1];
    push @aOfA, \@tmp;

    # Note that @tmp turns anonymous but doesn't dispose
    # at this reloop point
}