Norman H. Cohen. Type-Extension Type Tests Can Be Performed In Constant Time. ACM Transactions on Programming Languages and Systems, 13(4):626-629, 1991. [doi]
@article{Cohen91:0,
title = {Type-Extension Type Tests Can Be Performed In Constant Time},
author = {Norman H. Cohen},
year = {1991},
doi = {10.1145/115372.115297},
url = {http://doi.acm.org/10.1145/115372.115297},
tags = {testing},
researchr = {https://researchr.org/publication/Cohen91%3A0},
cites = {0},
citedby = {1},
journal = {ACM Transactions on Programming Languages and Systems},
volume = {13},
number = {4},
pages = {626-629},
}