@inproceedings{altenkirch-2007-observational, series={ICFP07}, title={Observational equality, now!}, url={http://dx.doi.org/10.1145/1292597.1292608}, DOI={10.1145/1292597.1292608}, booktitle={Proceedings of the 2007 workshop on Programming languages meets program verification}, publisher={ACM}, author={Altenkirch, Thorsten and McBride, Conor and Swierstra, Wouter}, year={2007}, month=Oct, pages={57–68}, collection={ICFP07} }