Illustration of the TSNPE algorithm applied to our pulsar population synthesis. Here, we show the results for inferring the seven free parameters related to the magneto-rotational evolution and the luminosity for the observed neutron star population, using 1000 simulations in the first round in Experiment 4. Each row corresponds to one round of inference. The last column shows the coverage probability computed on the test dataset. In each panel, the current round’s computed values are shown in blue, while values from previous rounds are shown in light grey. The grey shaded area in the one-dimensional marginal posterior represents the 95% credibility interval of the approximated posterior for that round. In each of these 1D marginal posterior distributions, the horizontal axes represent the parameters’ prior ranges. The results from Experiment 5 are qualitatively similar to those presented here.