Timing residuals of PSR J1640–4631 from MJD 56463 to 57298, 2013 September 29 to 2015 October 3, for the solution presented in Table 1. The top panel shows the timing residuals subtracting only the contributions from ν and ﹩\dot{\nu }﹩ with the dashed black line showing the fitted ﹩\ddot{\nu }﹩ of (3.38 ± 0.03) × 10⁻²² s⁻³. The bottom panel shows the residuals after accounting for ﹩\ddot{\nu }﹩. The gray bands in both panels indicate the 1σ timing model uncertainties.