The Infer option of the FIS menu graphically shows the inference mechanism. The input values are entered directly or by moving a cursor within each variable range. The inferred output value is displayed, together with several intermediate values, which allow to understand the different stages of the fuzzy reasoning:

For each rule:

Figure 5: Fuzzy inference in FisPro

Image infer1en  
Image rule1  

For each output:

The Price output being crisp, with a Sugeno defuzzification and a sum aggregation, the inferred value is simply a weighted average of the rule conclusions, where the weights are the rule matching degrees.

For any degree in the Degree input range, between 9 and 14, we get the corresponding price.

The price progression is smooth, due to the interpolating capacities of the FIS.