:: [[a]] -> [a] package:universe-base

Fair n-way interleaving: given a finite number of (possibly infinite) lists, produce a single list such that whenever v has finite index in one of the input lists, v also has finite index in the output list. No list's elements occur more frequently (on average) than another's.

Unfair n-way interleaving: given a possibly infinite number of (possibly infinite) lists, produce a single list such that whenever v has finite index in an input list at finite index, v also has finite index in the output list. Elements from lists at lower index occur more frequently, but not exponentially so.