1. sources of uncertainty in rules
   1. related to individual rules
      1. Antecedent
         1. Errors
         2. Likelihood of Evidence
         3. Combining of Evidence
      2. consequent
         1. Errors
         2. Likelihood of Evidence
   2. due to conflict resolution
      1. contradiction of rules
      2. subsumption of rules
      3. redundancy of rules
      4. missing rules
      5. data fusion
   3. due to incompatibility of rules
      1. explicit priority of rules
      2. implicit priority of rules
         1. speciality of patterns
         2. recency of facts matching patterns
         3. ordering of patterns
            1. lexicographic "lex"
            2. Means -Ends Analysis "MEA"
         4. order that rules entered
2. methods for dealing with uncertainty
3. Dempster-Shafer theory
4. theory of uncertainty based on fuzzy logic
5. commercial applications of fuzzy logic