Orbital orientation constraints for PSR J2222−0137. In the main panel we display the cos i − Ω plane, where randomly aligned orbits will have a priori constant probability density. The black contours show the 68.3% and 95.4% confidence region derived from a 3D χ² map of cos i − Ω − M space using the DDK model with the additional assumption that GR is the correct theory of gravity. The solid red lines indicate the regions that are consistent with the nominal and ±1σ measurements of ẋ, and the dashed vertical lines indicate the position of ς obtained in the ELL1H+ model. The dashed horizontal lines show the value of Ω from VLBI observations. The side panels display the 1D PDFs for cos i (top) and Ω (right). The solution with positive cos i has 99.66% of the total probability.