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Permutations sorted by a finite and an infinite stack in series

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 نشر من قبل Murray Elder
 تاريخ النشر 2017
  مجال البحث
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We prove that the set of permutations sorted by a stack of depth $t geq 3$ and an infinite stack in series has infinite basis, by constructing an infinite antichain. This answers an open question on identifying the point at which, in a sorting process with two stacks in series, the basis changes from finite to infinite.

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