∆χ² map on the plane of the planet parameters (log s, log q) of the lensing event KMT-2023-BLG-0416. The color scheme represents points with ∆χ² < 1²n (red), < 2²n (yellow), < 3²n (green), and < 4²n (cyan), where n = 2. The labels marked by A_in, A_out, B_in, and B_out represent positions of the four local solutions. The vertical dot-dashed line indicates the geometric mean between the binary separations of the B_in and B_out solutions.