Stefan Milius Tadeusz Litak Guard Your Daggers and Traces: On The Equational Properties of Guarded (Co-)recursion. FICS 2013 72-86 https://doi.org/10.4204/EPTCS.126.6 http://arxiv.org/abs/1309.0895 journals/corr/BaeldeC13 db/series/eptcs/eptcs126.html#MiliusL13