Visibility Rule states that other fauceirs are visible to a certain fauceir if and only if both can interact. And interaction usually requires common sub-fauceirs.
Visibility can be described qualitatively and quantitatively. Qualitative includes the two states visible or invisible only while quantitative description allows to define the degree of visibility. The degree of visibility is proportional to the degree of interaction or influence.
Two rule are reated:
- Rule of blindness
- Rule of dependence
