Inverted Distributions: Rare Inputs
Definition: a “rare” input value is one that is unlikely to be selected according to D, where D is the operational profile
Rare is a probability/selection issue, not an abnormality issue
If you perform the fault injection algorithms with D-1, you assess the safety of the program under unusual operating circumstances. Since you are very unlikely to test according to D-1, i.e., select the high-probability inputs of D-1 during test, this is valuable information