Many a times you are required to identify the numbers which may not be serially created or sometimes duplicate serial numbers may have crept in. Imagine searching them in a huge drawing. This requirement can be addressed using Sequence Check Lisp. Sequence Check Lisp displays all the missing serial numbers and duplicate serial numbers among the selected text value. It will consider a range for searching as minimum and maximum number among the selected text. If you have kept your command line window on then pressing F2 button after the command, to see the test result. This lisp finds its use in numbering parcels or any other requirements where a serial numbering system is required.