Last Run Index

Key Last Run Index of function Run in Taskrefers to an optional integer m that defines for each function ƒⁱ, what will be the last processed elements in the input arrays contained in the Values of the Key-Value pairs specified in the corresponding cell of the column titled #VaryingInput
Normally, each function ƒⁱ runs R times, where R is the number of elements in each of these arrays, while the last run corresponds to the arrays' last elements.
This is at least the case when m < k , where k is the index defined in key First Run Index

Note, if m is omitted, it assumes the default value of 0.
But if m is set to some positive value such that m ≥ k, ƒⁱ will run fewer times and its last run will involve processing of the mᵗʰ elements of the mentioned arrays.
The total number of runs for each function ƒⁱ will then be at most equal to m - k + 1, with the equality holding if the varying input arrays contain at least m - k + 1 elements.