Requirements in feature algebra

Feature Algebra is intended to capture the commonalities of feature oriented software development (FOSD), such as introductions, refinements and quantification. It allows denoting systems composed of features by algebraic terms and transforming the systems by manipulating the terms using the laws of the algebra. The algebraic view abstracts from differences of minor importance and leads to more compact and effective reasoning. While the existing Feature Algebra covers most of the main aspects of FOSD, so far requirements have not been integrated into it. They naturally arise in connection with different aspects of feature orientation, such as feature elicitation, feature dependence, mutual feature exclusion and feature interaction. This paper presents a possibility for integrating requirements into Feature Algebra