As seen before, the conclusion of a rule can be in the form of a combination of intersections, unions and negation of premises. In this case the following computations are done previously :

IF ... THEN       IF ... THEN       IF ... THEN !A

We compute a realization degree for each pixel and for each single premise at each pixel location. This is performed using fuzzy logic and morphological mathematics, for example for 3D distance computation in a Digital Elevation Model.