#!/usr/bin/perl

my $set = [qw/A000 A123-A456 A999-B000 B789-B888/];
my %elements;

for (@$set) {
    /-/ or $elements{$_} = undef or next;
    if ( /([[:alpha:]]\d{3})-([[:alpha:]]\d{3})/ ) {
        my $start = $1;
        do { $elements{$start} = undef }
            while $start++ ne $2;
    }
}

while (<DATA>) {
    chomp;
    print "$_ is ",
          (exists $elements{$_} ? '' : 'not '),
          'in the set.',
          $/;
}

__DATA__
A000
A001
A122
A123
A124
A154
A320
A455
A456
A457
A530
A779
A932
A998
A999
B000
B001
B123
B666
B788
B789
B790
B820
B887
B888
B889
B900