Abstract
We give simple, self-contained proofs of the basic hardness results for the classes W[t] of the weft hierarchy. We extend these proofs to higher levels of the hierarchy and illuminate the distinctions among its classes. The anti-monotone collapse at W[\(\mathit{1,s}\)] and the normalization of weft-t formulas arise as by-products of the proofs.
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Buss, J.F., Islam, T. (2004). Simplifying the Weft Hierarchy. In: Downey, R., Fellows, M., Dehne, F. (eds) Parameterized and Exact Computation. IWPEC 2004. Lecture Notes in Computer Science, vol 3162. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-28639-4_17
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DOI: https://doi.org/10.1007/978-3-540-28639-4_17
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-23071-7
Online ISBN: 978-3-540-28639-4
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