We describe how the concept of program slicing can be formalised in WSL transformation theory. This formalism naturally tends itself to several generalisations including amorphous slicing and conditioned slicing. One novel generalisation is "semantic slicing" which combines slicing and abstraction to a specification. Interprocedural semantic slicing has been implemented in the FermaT transformation system (Ward, 1999): an industrial-strength transformation system designed for forward and reverse engineering, re-engineering and program comprehension.
['M. Ward']
Program slicing via FermaT transformations