Continuum-wise expansiveness and specification for set-valued functions and topological entropy

We define the concept of continuum-wise expansiveness for set-valued functions. We prove that for a compact metric space X X with positive topological dimension, if a set-valued function is c w cw -expansive, then its topological entropy is positive. We also introduce the notion of point-wise specification property for set-valued functions and prove that set-valued functions with this property have positive entropy.