Knowledge can be expressed succinctly in the Probabilistic Logic 1 IntroductionĪ wide variety of models that combine logical and statistical This paper is under consideration for acceptance in TPLP. We evaluate the effectiveness of the proposed techniques through experiments on several problems. Secondly, the approximate technique is a generalization of likelihood weighting in Bayesian Networks, and allows us to perform sampling-based inference with lower rejection rate and variance. Firstly, the exact inference procedure is a generalization of traditional inference, and results in speedup over the latter in certain settings. We describe a program transformation technique to construct OSDDs via query evaluation, and give procedures to perform exact and approximate inference over OSDDs.
We propose a data structure called Ordered Symbolic Derivation Diagram (OSDD) which captures the possible worlds by means of constraint formulas. While this approach saves inference time due to substructure sharing, there are a number of problems where a more compact data structure is possible. Systems such as ProbLog, PITA, etc., use propositional data structures like explanation graphs, BDDs, SDDs, etc., to represent the possible worlds. In PLP, inference is performed by summarizing the possible worlds which entail the query in a suitable data structure, and using it to compute the answer probability. Probabilistic Logic Programs (PLPs) generalize traditional logic programs and allow the encoding of models combining logical structure and uncertainty.