The present invention proposes a continuous multi-parameter version of Diffie-Hellman protocol based on matrices over topological monoids. The rotating magnetic field can be used to obtain rotating-field NMR spectra, such as magic angle spinning spectra, without having to physically rotate the sample. A first substrate having a pixel array in the display area is provided. The first and the second walls are spaced from each other in a direction that is along the mount surface and crosses a laser beam emission direction of the semiconductor laser element, with the semiconductor laser element arranged between the first and the second walls. Based on the evaluations, feedback can be provided to an annotator making the annotations.