A multiply proven attribute is an attribute that appears as the conclusion attribute of more than one rule (including shortcut rules).
An attribute which is proven by multiple rules like this will not function correctly in the Engine because of the operation of the automatic alternate conclusion in every rule. The closed logic of alternative conclusions will prevent multiple rules being traversed - the first rule traversed will close off the possibility of the other forms operating.
Prove an attribute using multiple rules
Check my rules for multiply proven attributes
The nature of the business rule domain and methodological factors may mean you need to have attributes with multiple, or distributed (non-adjacent), proofs in your rulebase. For such rules it is necessary to designate the rule as a 'rule fragment'. A 'priority' needs to also be specified for these rules if the fragments are concluding different values (ie anything other than boolean fragments that all conclude true). This guarantees predictable question searches and inferencing.
To create rule fragments:
You will notice that your rules in Word are now preceded by a configuration line which indicate that the rule is a rule fragment and shows the priority.
At build time, rules marked as rule fragments will be automatically combined into a single rule using an inclusive or operator, and use the author-assigned priorities to determine the question order. Lower numbers indicate higher priority (ie priority 1 takes precedence over priority 2 rule fragments).
A rule without a proof becomes the default alternative conclusion for the collection of rules if it has a lower priority than the other rules. So, for example, if you wanted to specify an otherwise clause for these rule fragments:
rule_property[fragment:1]
the person is happy if
the person is on holiday
rule_property[fragment:2]
the person is happy if
the person has been caught speeding
You would need to also have a rule without conditions which specifies the alternative conclusion, ie:
rule_property[fragment:3]
the person is happy
Then if the person is not on holiday and has not been caught speeding then the result would be true (the person is happy).
If this alternative conclusion rule is not provided, the result will be uncertain when the other rules are disproven. That is, if the person is not on holiday and the person has not been caught speeding then the result would be uncertain.
Oracle Policy Modeling automatically runs a check for Multiply Proven Attributes when building a rulebase. If any multiple proven attributes are detected, an error will be logged in the Error List and the build will be canceled. To see which attributes are proven by more that one rule, you can generate a Multiply Proven Attributes Report. To do this, select Reports | Multiply Proven Attributes from the main menu in Oracle Policy Modeling.
NOTE: Attributes that are concluded in rules marked as rule fragments will not fail the Multiply Proven Attributes check at build time, and will not appear in the Multiply Proven Attribute report.