“…Experiments in the practical application of these techniques by Holt et al [24,25], Müller et al [26,27,28], Klint et al [29,30,31], Sneed [32,33] and others have shown that they are practical and useful in industry. Moreover, the success of companies such as Legasys Corporation, Formal Systems, Semantic Designs and others using design recovery and other formal analysis techniques to attack the Year 2000 ("Y2K") problem have demonstrated that large productivity gains and cost reductions can be obtained when software maintenance is assisted by program comprehension.…”