Investigating Quantum Cause-Effect Graphs

Abstract

Cause-effect graphs have shown promising results in identifying relations among causes and effects of classical software systems, followed by designing effective test cases from them. Towards this end, we investigate the use of cause-effect graphs for quantum pro-grams. Classical cause-effect graphs apply classical logic (e.g., AND, OR) to express these relations, which might not be practical for describing similar relations in quantum programs due to quantum superposition and entanglement. Thus, we propose an extension of cause-effect graphs, where quantum logic inspired functions (e.g., Hadamard) and their generalizations are defined and applied. Moreover, we present a metamodel describing various forms of cause-effect graphs. Finally, we demonstrate a possible method for generating test cases from a quantum cause-effect graph applied to a Bell state quantum program. Lastly, the design and utility of the resulting testing method is discussed, along with future prospects for general quantum cause-effect graphs.