For each package P = {x 1 , x 2 , ..., x N } containing N relational paths, we encode the package to a realvalued matrix as: where x n ∈ R k is the k-dimensional path embedding and ⊕ denotes the concatenation operator for the package representation p ∈ R N ×k .
given a relational path x = {r 1 , r 2 , ...r t , ...}, the path embedding x is encoded as: where each relation r t is mapped into a real-valued embedding r t ∈ R k pre-trained by TransE (Bordes et al., 2013).