In this hypothesis, pneumonia was unspecified. Specifying that pneumonia is false further determines the time of PC.
The probability of the MI producing low LVF is 0.6. Since the low LVF ended before now, it normalized in less than 6 hours, for which the probability is 0.3. The probability of low LVF producing high LAP is 0.8. There are two regions in which to consider the high LAP. Either it ended before the nitroglycerin started or it continued for some time after the nitroglycerin started but ended before now. This decision does not determine which nodes are in the hypothesis, so it is left undetermined. Finally, the probability of high LAP causing PC depends on how long the high LAP has been present. We know it happened in less than 6 hours, but not whether it happened in less than one hour. Again, the decision also does not determine which nodes are in the hypothesis, so the time interval is left unchanged and the higher probability is picked. The probability that the PC normalized in less than 6 hours is zero, so no further adjustment is necessary and the total estimated probability is the product of the probabilities.