 tensor X is expressed as:
% 
% $${\mathcal X} = {\mathcal G} \times_1 A \times_2 B \times_2 C$$
% 
% In MATLAB notation, |X=ttm(G,{A,B,C})|. The |ttensor| class stores the
% components of the tensor X and can perform many operations, e.g., |ttm|,
% without explicitly forming the tensor X.
%% Creating a ttensor with a tensor core
core = tensor(rand(3,2,1),[3 2 1]); %<REPLACE_WITH_DASH_DASH The core tensor.
U = {rand(5,3), rand(4,2), rand(3,1)}; %<REPLACE_WITH_DASH_DASH The matrices.
X = ttensor(core,U) %<RE