Posterior distributions of the most important internal structure parameters for HIP 29442 b, namely the mass fractions of an inner core, mantle and envelope in the planet as well as the mass fraction of water in the envelope. The top row shows the posteriors assuming a prior consistent with the planet forming outside the iceline (case A), while the middle row uses a prior that is consistent with the planet forming inside the iceline (case B). For both water priors, we show the posteriors for three different compositional priors: first assuming that the planet has stellar Si/Mg/Fe ratios (purple), second assuming that the planetary bulk Si/Mg/Fe ratios are iron-enriched compared to the host star (pink) and third sampling the planetary bulk Si/Mg/Fe uniformly from the simplex on which the molar fractions add up to 1 (blue). The bottom row shows the posterior distributions of the mass fractions of an inner core, mantle, condensed water layer and separately modelled H/He envelope with respect to the total planet mass when applying the previously used version of the model assuming stellar Si/Mg/Fe ratios. The dashed vertical lines show the median value of each distribution. The dotted lines show the priors.