observation it's not in the silicone paddle with everything that's following so they've just computed the most likely x0 we'll say for every x0 we're going to calculate how likely it is given the evidence we've seen so far from there we'll then say once we have that we can combine that with the model for x1 given x0 and observation for z1 given x1 to find how likely each x1 is if we match it with the best x0 for that x1 so essentially saying for each x1 how likely is it if I get to match it with the best the most compatible x0 that's