  This paper presents a solution to the Flowgraphs case study for the
Transformation Tool Contest 2013 (TTC 2013). Starting from Java source code, we
execute a chain of model transformations to derive a simplified model of the
program, its control flow graph and its data flow graph. Finally we develop a
model transformation that validates the program flow by comparing it with a set
of flow specifications written in a domain specific language. The proposed
solution has been implemented using ATL.
