The syntax of Milord II rules is given in Figure 8. The rules are composed of an identifier, the premise (that is, a conjunction of conditions), the conclusion, the certainty value of the rule, and, optionally, a documentation string. The certainty value of a rule is a linguistic term belonging to the local logic of the module.
Figure 8: Syntax of rule definition.
Facts are the basic elements used to build rules. They appear in the conditions and in the conclusion of rules. Class facts have no value and do not appear in the rules. The evaluation of a condition or a conclusion must always be an interval of truth-values. Then, in the case of facts whose type is neither boolean nor many-valued nor fuzzy, the language is provided with a set of predefined predicates that apply on them to produce as result intervals of truth values, and hence can be used as conditions of rules.