Ralf Lämmel, Jörg Harm. Test case characterisation by regular path expressions. In Proc.\ Formal Approaches to Testing of Software (FATES'01). Notes Series NS-01-4, pages 109-124, BRICS, august 2001. [doi]
A signature-parametric (say generic) framework for test case characterisation, and definition of test set coverage criteria is developed. The signature might correspond to a programming language syntax, the format of a data structure, a computational or semantical structure, e.g., for derivations, proof trees, or control-flow graphs. Test set characterisation is based on regular expressions describing paths for terms over the signature at hand. Necessary and convenient properties for test set coverage criteria can be conceived in the framework.