1. Completeness for the Complexity Class ∀∃R and Area-Universality.
- Author
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Dobbins, Michael Gene, Kleist, Linda, Miltzow, Tillmann, and Rzążewski, Paweł
- Subjects
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ALGEBRA , *PLANAR graphs , *LOGICAL prediction , *POLYNOMIALS , *ANALOGY - Abstract
Exhibiting a deep connection between purely geometric problems and real algebra, the complexity class ∃ R plays a crucial role in the study of geometric problems. Sometimes ∃ R is referred to as the 'real analog' of NP. While NP is a class of computational problems that deals with existentially quantified boolean variables, ∃ R deals with existentially quantified real variables. In analogy to Π 2 p and Σ 2 p in the famous polynomial hierarchy, we study the complexity classes ∀ ∃ R and ∃ ∀ R with real variables. Our main interest is the AreaUniversality problem, where we are given a plane graph G, and ask if for each assignment of areas to the inner faces of G, there exists a straight-line drawing of G realizing the assigned areas. We conjecture that AreaUniversality is ∀ ∃ R -complete and support this conjecture by proving ∃ R - and ∀ ∃ R -completeness of two variants of AreaUniversality. To this end, we introduce tools to prove ∀ ∃ R -hardness and membership. Finally, we present geometric problems as candidates for ∀ ∃ R -complete problems. These problems have connections to the concepts of imprecision, robustness, and extendability. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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