Supported by the Natural Science Foundation of China(No.11471097);the Innovative Fund Project of Hebei Province(sj.2017084)
Let F denote the folded (2D + 1)-cube with vertex set X and diameter D ≥ 3. Fix x∈ X. We first define a partial order ≤ on X as follows. For y,z ∈ X let y ≤ z whenever (x,y)+ (y,z) =- (x, z). Let R ...