Robbie rules for the use of the limit of Notes Summary of a dollar in the function of the limits of computing, including the limits of a class of infinitive can not be used "to the limit equal to the limit to" the rule of law and Robbie is the calculation of such an effective way to limit infinitive. Robbie reached the limits of the law to provide a new computing possibilities, it also brings a great convenience. However, if the blind use of sub-rule will lead to error. Robbie rules of this article will use some of the problems encountered in the analysis of research, pointed out that in the process of using the Notes and the scope of application of the limit order to enrich the way up to Robbie and to promote the application of the law, given Romania than the law of series in order to limit and isolate the type of singular point at the time of application, are summarized in the mathematical analysis and complex variable function with Robbie similar rules of law, so that we can be more convenient to determine the isolated singular point. Keywords Limit; infinitive; Robbie of law