Roots search performed by the Multipoly algorithm exploring a configuration of three lenses. These lenses are marked in gray, numbered (1), (2), and (3) in order of increasing mass, reflecting the sequential order in which the algorithm constructs the polynomials centered on each respective lens. The respective critical curve is also shown. The source position is indicated in the caustics box. The algorithm begins its search for roots near the smallest lens and gradually moves toward the more massive lenses. The order in which the roots are found is denoted by the numbers, while the color corresponds to the polynomial from which they were derived; the polynomial is centered in the lens with a border of the same color. The darker roots represent real images, while the lighter colored roots are classified as ghost images.