License: Creative Commons Attribution 4.0 International license (CC BY 4.0)
When quoting this document, please refer to the following
DOI: 10.4230/LIPIcs.ICALP.2022.34
URN: urn:nbn:de:0030-drops-163751
Go to the corresponding LIPIcs Volume Portal

Caballero, David ; Gomez, Timothy ; Schweller, Robert ; Wylie, Tim

Unique Assembly Verification in Two-Handed Self-Assembly

LIPIcs-ICALP-2022-34.pdf (1 MB)


One of the most fundamental and well-studied problems in tile self-assembly is the Unique Assembly Verification (UAV) problem. This algorithmic problem asks whether a given tile system uniquely assembles a specific assembly. The complexity of this problem in the 2-Handed Assembly Model (2HAM) at a constant temperature is a long-standing open problem since the model was introduced. Previously, only membership in the class coNP was known and that the problem is in P if the temperature is one (τ = 1). The problem is known to be hard for many generalizations of the model, such as allowing one step into the third dimension or allowing the temperature of the system to be a variable, but the most fundamental version has remained open.
In this paper, we prove the UAV problem in the 2HAM is hard even with a small constant temperature (τ = 2), and finally answer the complexity of this problem (open since 2013). Further, this result proves that UAV in the staged self-assembly model is coNP-complete with a single bin and stage (open since 2007), and that UAV in the q-tile model is also coNP-complete (open since 2004). We reduce from Monotone Planar 3-SAT with Neighboring Variable Pairs, a special case of 3SAT recently proven to be NP-hard. We accompany this reduction with a positive result showing that UAV is solvable in polynomial time with the promise that the given target assembly will have a tree-shaped bond graph, i.e., contains no cycles. We provide a ?(n⁵) algorithm for UAV on tree-bonded assemblies when the temperature is fixed to 2, and a ?(n⁵log τ) time algorithm when the temperature is part of the input.

BibTeX - Entry

  author =	{Caballero, David and Gomez, Timothy and Schweller, Robert and Wylie, Tim},
  title =	{{Unique Assembly Verification in Two-Handed Self-Assembly}},
  booktitle =	{49th International Colloquium on Automata, Languages, and Programming (ICALP 2022)},
  pages =	{34:1--34:21},
  series =	{Leibniz International Proceedings in Informatics (LIPIcs)},
  ISBN =	{978-3-95977-235-8},
  ISSN =	{1868-8969},
  year =	{2022},
  volume =	{229},
  editor =	{Boja\'{n}czyk, Miko{\l}aj and Merelli, Emanuela and Woodruff, David P.},
  publisher =	{Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
  address =	{Dagstuhl, Germany},
  URL =		{},
  URN =		{urn:nbn:de:0030-drops-163751},
  doi =		{10.4230/LIPIcs.ICALP.2022.34},
  annote =	{Keywords: self-assembly, unique assembly verification, 2-handed assembly model}

Keywords: self-assembly, unique assembly verification, 2-handed assembly model
Collection: 49th International Colloquium on Automata, Languages, and Programming (ICALP 2022)
Issue Date: 2022
Date of publication: 28.06.2022

DROPS-Home | Fulltext Search | Imprint | Privacy Published by LZI