non-interaction edge type

[fatcatZF]

For the system in which 2 particles interact or not, such as the spring experiments, if we use z_{ij}=[0,1] to denote interaction, and z_{ij} = [1,0] to denote non-interaction(no message between node i and j), in the decoder should we only consider the interaction edge type, i.e., h^t_(i,j) = z_{ij,0}fe([x^t_i, x^t_j])? Since no message between the non-interaction edge.