Well, de facto they always converge, mugging or not, and I'm not going to take as normative a formalism where they do diverge. edit: e.g. instead I can adopt speed prior, it's far less insane than incompetent people make it out to be - code size penalty for optimizing out the unseen is very significant. Or if I don't like speed prior (and other such "solutions"), I can simply be sane and conclude that we don't have a working formalism. Prescriptivism is silly when it is unclear how to decide efficiently under bounded computing power.