Fig. 1.
(A) Simple Bayesian network for cancer detection. T denotes the waiting time for the tumor, Ts the time of diagnosis. The disease is present, X=1, if T<Ts. Yet the diagnosis Y may contain errors. (B) Graph of an H-CBN example. The waiting times Ti of the mutations i=1,…, 4 evolve according to the CBN depicted in the upper left: mutations 1 and 2 arise independently; mutation 3 can only occur after 1, T1<T3, mutation 4 occurs only if both 1 and 2 are present, T1, T2<T4. A mutation i is present in the genotype X=(X1,…, X4) if Ti<Ts, where Ts is the independent stopping time. The observations Y=(Y1,…, Y4) contain errors that occur independently for each mutation.