# Example 2: lamppost tricks

Building on the reasoning underlying the “lamp post trick”, which restricts a search for a lost item to the area illuminated by a lamp post, it is apparently as easy to simplify the task of dealing with severe uncertainty. The trick here is to … **ignore** the severity of the uncertainty. For instance, in cases where the severity of the uncertainty is manifested in a vast uncertainty space, then analogously to searching under the lamp post, this trick instructs to confine the analysis to a **small neighborhood** of this space. This proposition is illustrated below, where the large rectangle represents the uncertainty space and the small yellow rectangle represents the neighborhood of the uncertainty space on which the analysis is conducted. The black area is … completely ignored.

It seems that this trick should prove particularly effective in cases where the severity of the uncertainty is manifested in an **unbounded** space. The proof: info-gap decision theory. Indeed, this is the secret weapon that this theory deploys to tackle cases where the severe non-probabilistic uncertainty is characterized by an **unbounded** uncertainty space.