 There are more proposals to deal with the issue of probability in the MWI. Barrett 2017 argues that for a derivation of the Probability Postulate it is necessary to add some assumptions to unitary evolution. For example, Weissman 1999 has proposed a modification of quantum theory with additional non-linear decoherence (and hence with even more worlds than in the standard MWI) which can lead asymptotically to worlds of equal mean measure for different outcomes. Hanson 2003, 2006 proposed decoherence dynamics in which observers of different worlds “mangle” each other such that an approximate Born rule is obtained. Van Wesep 2006 used an algebraic method for deriving the probability rule, whereas Buniy et al. 2006 used the decoherent histories approach of Gell-Mann and Hartle 1990. Waegell and McQueen 2020 considered probability based on the ontology of `local worlds’ introduced by Waegell 2018, which is a concept inspired by the approach of Deutsch and Hayden 2000.