 Thus instead of having a "winner takes all" strategy where the most probable HMM is selected as an observation symbol, the likelihood formula_17 of observing the formula_4th HMM can be used in the recursion formula of the level formula_6 HMM to account for the uncertainty in the classification of the HMMs at level formula_15.Thus, if the classification of the HMMs at level formula_21 is uncertain, it is possible to pay more attention to the a-priori information encoded in the HMM at level formula_6.A LHMM could in practice be transformed into a single layered HMM where all the different models are concatenated together.