“…Known methods for linguistic analysis of informal natural-language requirements are developing within the NLP scope, so they allow a lot of disadvantages, but, in addition, they "miss a methodology for an adequate formal analysis of the requirements" (Cimatti et al, 2009). On the contrary, methods that are aimed at creating formal model-based specifications and use formal specification notations such as Z-language (Madhan et al, 2017) have sufficiently developed means for formal analysis of the functional requirements specifications. Based on set theory and first-order predicate logic, such notations are as expressive as they are poor for semantic analyses, therefore "they frequently ignore developers' needs, target specific development models, or require translation of requirements into tests for verification; the results can give out-of-sync or downright incompatible artifacts" (Naumchev et al, 2017).…”