  Probabilistic context free grammars (PCFG) have been the core of the
probabilistic reasoning based parsers for several years especially in the
context of the NLP. Multi entity bayesian networks (MEBN) a First Order Logic
probabilistic reasoning methodology is widely adopted and used method for
uncertainty reasoning. Further upper ontology like Probabilistic Ontology Web
Language (PR-OWL) built using MEBN takes care of probabilistic ontologies which
model and capture the uncertainties inherent in the domain's semantic
information. The paper attempts to establish a link between probabilistic
reasoning in PCFG and MEBN by proposing a formal description of PCFG driven by
MEBN leading to usage of PR-OWL modeled ontologies in PCFG parsers.
Furthermore, the paper outlines an approach to resolve prepositional phrase
(PP) attachment ambiguity using the proposed mapping between PCFG and MEBN.
