On relating blackboards in the μLog coordination model

We describe coordination relations, that are relations that induce the presence of data on some data spaces from the presence of other data on other data spaces. To that end we build upon previous work on the μLog model and show that the coordination relations can be easily incorporated in it. Part of this incorporation is achieved through the use of multiple blackboards and processes running on them. The remaining effort is achieved by means of auxiliary operators involving multiple conditional read operations. Although simple, the form of coordination relations we propose are quite powerful as evidenced by a few examples including relations coming from the object-oriented paradigm such as data space inheritance, merge and relations involving constraints