Table 1.

Notations of Variables

Notation	Explanation
S	The total number of sentences
|R|	The total number of latent relations
N	A random variable to represent the total number of relation pairs in a sentence
|F|	The total number of features in each mention
«1:R	R-dimensional parameter of a Dirichlet distribution for relations
${\beta }_{1:R}^f$	Parameters for R component distribution over relation features
${\beta }_{1:R}^{\left\{w,v\right\}}$	Parameters for R component distribution over drug entity 1 (w) or entity 2 (v)
${\beta }_{1:F}^{\left\{y,z\right\}}$	Parameters for F component distribution over features of drug entity 1 (y) or entity 2(z)
θ1:R	R-dimensional parameters of relation distribution variables over a sentence
${\varnothing }_{1:R}^f$	Parameters for R component distribution over the relation types
${\varnothing }_{1:R}^{\left\{w,v\right\}}$	Parameters for R component distribution over drug entity 1 (w) or entity 2(v)
${\varnothing }_{1:F}^{\left\{y,z\right\}}$	Parameters for F component distribution over features of drug entity 1
r1:N	Variables representing a sequence of relations in a specific sentence
f	Features of a given relation pair
{W, V}1:N	Variables representing hidden variable, the drug entity 1(w) or entity 2(v) in a specific sentence
{y,z}1:R	Finite set of observed variables that represents a specific features of drug entity 1(w) or entity 2(v)