Linearisability on datalog programs

TL;DR: In this paper, the authors propose a variant of the Relational Algebra equipped with a fixpoint operator for expressing recursive relational queries, which can notably express unions of conjunctive regular path queries.

TL;DR: Weakly linear disjunctive datalog as mentioned in this paper is a rule-based language that extends both datalog and linear disjoint datalog, and for which reasoning is tractable in data complexity.

TL;DR: It is shown that piece-wise linear recursion alone, without the wardedness condition, is not enough as it leads to the undecidability of reasoning, and the relative expressiveness of the query languages based on (piece-wiselinear) warded sets of TGDs is studied.

TL;DR: In this paper, the authors show that checking satisfiability of a set of non-linear Horn clauses (also called a nonlinear Horn clause program) can be achieved using a solver for linear Horn clauses.

TL;DR: In this paper the operational and fixpoint semantics of predicate logic programs are defined, and the connections with the proof theory and model theory of logic are investigated, and it is concluded that operational semantics is a part ofProof theory and that fixpoint semantic is a special case of model-theoretic semantics.

TL;DR: This paper shows how to recursively run the learning algorithm for each value using the oracles of the target and builds a decision tree according to the possible values of this attribute to continue the learning process.

TL;DR: Computational complexity is the realm of mathematical models and techniques for establishing impossibility proofs for proving formally that there can be no algorithm for the given problem which runs faster than the current one.