Before revision:  we differentiate between "integral" exposure (when we care for how long the path sees every point of the domain) and "0/1" exposure (just counting whether a point is seen by the path or not).
After revision:  we differentiate between "integral" exposure (when we care for how long the path sees every point of the domain) and 0/1 exposure (just counting whether a point is seen by the path or not).