QRB-Domains and the Probabilistic Powerdomain
arXiv:1202.2287 · doi:10.2168/LMCS-8(1:14)2012
Abstract
Is there any Cartesian-closed category of continuous domains that would be closed under Jones and Plotkin's probabilistic powerdomain construction? This is a major open problem in the area of denotational semantics of probabilistic higher-order languages. We relax the question, and look for quasi-continuous dcpos instead. We introduce a natural class of such quasi-continuous dcpos, the omega-QRB-domains. We show that they form a category omega-QRB with pleasing properties: omega-QRB is closed under the probabilistic powerdomain functor, under finite products, under taking bilimits of expanding sequences, under retracts, and even under so-called quasi-retracts. But... omega-QRB is not Cartesian closed. We conclude by showing that the QRB domains are just one half of an FS-domain, merely lacking control.
32 pages, 7 figures. An extended abstract already appeared in Proc. 25th Annual IEEE Symposium on Logic in Computer Science (LICS'10)