of rough set models in probability terms as can be viewed from a probability distribution in Figure 3.

![0_image_0.png](0_image_0.png)

## Rule Extraction

Once Bayesian RST was applied to the HIV data, unique distinguishable cases and indiscernible cases were extracted. From the data set of 12945 cases, the data is only a representative of 452 cases out of the possible 4096 unique combinations. The lower approximation cases are rules that always hold, or are definite cases while the upper approximation can only be stated with certain plausibility. Examples of both cases that were extracted from the approach in this paper are stated below: