@inproceedings{1596559,
 author = {Liu, Hai and Cheng, Eric and Hudak, Paul},
 title = {Causal commutative arrows and their optimization},
 booktitle = {ICFP '09: Proceedings of the 14th ACM SIGPLAN international conference on Functional programming},
 year = {2009},
 isbn = {978-1-60558-332-7},
 pages = {35--46},
 location = {Edinburgh, Scotland},
 doi = {http://doi.acm.org/10.1145/1596550.1596559},
 publisher = {ACM},
 address = {New York, NY, USA},
 }