“…This property is utilised in, for example, Perelman et al (2016) and Shamaiah, Banerjee, and Vikalo (2010), and if satisfied, a heuristic function would also be easy to compute. However, the amount of distinguishability that is increased for each fault pair D S∪{y l } i,j (θ ), when adding a sensor y l , depends on the previous selected set of sensors S. If S 1 , S 2 ⊆ S \ {y l } are two sets of sensors such that S 1 ⊆ S 2 , then…”