Aims are detailed in the Aims file.

The main file is isbn_master. 
It requires IsbnClass and CsvLineClass, together with an input csv file. 
It will generate as output a csv file recording if the input strings are valid or not.

Isbn_test runs a suite of tests for the IsbnClass.

Generate_isbn creates a file containing valid isbn numbers. 
A lazy enumarator is used to generate potential isbn numbers, that are then constrained by first digit.
A given number of output isbn numbers is defined.