docs/fig/tensors_mps_no_names.tikz
\directlua{mpt.defaults['tensor_width'] = 2}
\directlua{mpt.defaults['len_horizontal_legs'] = 0.25}
\directlua{mpt.defaults['len_vertical_legs'] = 0.5}
\directlua{mpt.draw_node({S=4}, {tensor_name='A', x=-2})}
\node at (0,0) {\Huge $=$};
\directlua{mpt.draw_mpa(4, {S=1}, {tensor_name='B', x=2})}