The predictor H Boost returned by our boosting algorithm is based on a scoring function h : X × Y → R, which, as for standard ensemble algorithms such as AdaBoost, is a convex combination of base scoring functions h t : h = T t=1 α t h t , with α t ≥ 0.
the base scoring functions used in our algorithm have the form these can be derived from the path experts in H by letting h k t (x, y) = 1 h k t (x)=y k .