Thus POS N-grams predict word relations only in a probabilistic sense.
to transform Pr(R | r, t) into a form we can estimate, we first apply the definition of conditional probability: to estimate the numerator Pr(R, t, r), we first marginalize over the POS N-gram p: We expand the numerator using the chain rule: Cancelling the common factor yields: We approximate the first term Pr(R | p, t, r) as Pr(R | p), based on the simplifying assumption that R is conditionally independent of t and r, given p. we assume that given a POS N-gram, the target and relative words t and r give no additional information about the probability of a relation.