a first variant within the bayesian version is to come up with a proper prior probability distribution of the smaller amount of money in the two envelopes, such that when step 6 is performed properly, the advice is still to prefer envelope b, whatever might be in envelope a. so though the specific calculation performed in step 6 was incorrect (there is no proper prior distribution such that, given what is in the first envelope a, the other envelope is always equally likely to be larger or smaller) a correct calculation, depending on what prior we are using, does lead to the result formula_15 for all possible values of "a".