This paper is an exploratory work were the authors study how the technology of Formal Methods (FM) can interact with agile process in general and with Extreme Programming (XP) in particular. Our thesis is that most of XP practices (pair programming, daily build, the simplest design or the metaphor) are technology independent and therefore can be used in FM based developments.

One of the most important problems in software development is the gap between the intended behaviour of a program (i.e. the specification) and the final result. We believe that the use of formal specifications in combination with a system able to generate (verified) code from them, integrated in an Iterative Rapid Prototyplng Process environment could be a solution to this problem.

Research in automated pattern detection from source code has focused on the efficiency of pattern extraction mechanisms; there are fewer projects on making the act of pattern definition easier and more accessible to practicing software engineers. We have developed the Program-Structured Pattern Definition Language (PsPDL) with the goal of giving programmers a familiar notation (more algorithmic, less mathematical) with which to create new pattern definitions for the catalogs that drive pattern recognition tools. The syntax of PsPDL resembles that of Java, with a few additional constructs added to express first-order or set theoretic concepts (such as quantification over identifiers); PsPDL also includes a simple module system that faciliates reusing pattern definitions. The semantics of PsPDL are based on a translation to first-order logic with a focus on modeling the dependencies among the semantic entities of OO programs. PsPDL is a first step towards solving the problem of training pattern catalogs directly in programming language source code.