Mass-mass diagram of J2222−0137. In the main panel on the left we display the cos i − M_c plane, and on the right we display the M_p − M_c plane; the grey region is excluded by the constraint sin i ≤ 1. The black contours indicate the 68.3% and 95.4% confidence region derived from a 3D χ² map of the cos i − Ω − M plane using the DDK orbital model combined with GR equations. The constraints (according to GR) from h₃, ς, and in the ELL1H+ model are shown in blue, green, and red lines, respectively, where the solid and dotted lines indicate the nominal and ±1σ measurements. The fact that they all meet in the same regions of these planes represents a ∼1% test of GR, which the theory passes. The side panels display the 1D PDFs for cos i (top left), M_p (top right), and M_c (right), with the median value and the 1σ and 2σ confidence intervals indicated as vertical lines.