substitutionGroup use of hyphens within square brackets in regular expressions [a-c] use of hyphens within square brackets in regular expressions [abc-[c]] use of hyphens within square brackets in regular expressions [-abc] use of hyphens within square brackets in regular expressions [bc-] invalid instance use of hyphens within square brackets in regular expressions [a-c] invalid instance use of hyphens within square brackets in regular expressions [abc-[c]] invalid instance use of hyphens within square brackets in regular expressions [-abc] invalid instance use of hyphens within square brackets in regular expressions [bc-]