Our goal is to generalize the well known bottom-up, set-oriented query evaluation for deductive databases in two aspects: First, we consider arbitrary clauses as rules in the database, not only Horn clauses or clauses with stratified negation. This allows to represent disjunctive information, in the database as well as in answers to queries. We utilize NF2 relations for modelling sets of disjun...

evolved to promote and integrate virus production with VS formation. In addition to initiating signal transduc-tion in the infected cell, adhesion molecule engagement at the VS ostensibly activates the uninfected target cell. Activation would ensure expression of virus receptors by the uninfected cell and promote virus replication once the virus has entered its new target. The identity of the H...

Memoization, such as that performed by bottom-up evaluation, helps detect loops, avoid repeated computation when subgoals are generated repeatedly, and in conjunction with a fair search strategy, ensures that evaluation is complete. Programs that generate non-ground facts (i.e., facts containing universally quantiied variables) and also need memoization are important in several contexts. Curren...

In PEPA, the calculation of the transitions enabled by a process accounts for a large part of the time for the state space exploration of the underlying Markov chain. Unlike other approaches based on recursion, we present a new technique that is iterative—it traverses the process’ binary tree from the sequential components at the leaves up to the root. Empirical results shows that this algorith...