Nonindependent Session Recommendation Based on Ordinary Differential Equation

Table 1

Global symbols definition.

Symbol	Meaning
	Session graph. denotes a node in the graph, and denotes an edge between the nodes
	The embedding vector of the session graph
	A single layer representation of a gated graph neural networks
	They represent each moment in the graph and the current gradient
	Adjoint. It represents the dependence of the descending gradient on the hidden state at each time point
	Potential state of time t
	Initial state of time t
	Terminal state of time t
	Ordinary differential equation solver
	It represents the sampled output at any time t obtained by the ODE solver
	It represents the posterior probability of the sampled output. Specifically, it represents the probability of the item to be recommended