An almost complete set A for a complexity class C is a language of C which is not complete, but that has the property that ``many'' languages of C reduce to A, where the term ``many'' is used in reference to Lutz's resource bounded measure (rbm). The question of the ... more >>>

We prove that all of the following assertions are equivalent:
There is a many-one complete disjoint NP-pair;
there is a strongly many-one complete disjoint NP-pair;
there is a Turing complete disjoint NP-pair such that all reductions
are smart reductions;
there is a complete disjoint NP-pair for one-to-one, invertible ... more >>>

We study small degree graph problems such as Maximum Independent Set
and Minimum Node Cover and improve approximation lower bounds for
them and for a number of related problems, like Max-B-Set Packing,
Min-B-Set Cover, Max-Matching in B-uniform 2-regular hypergraphs.
For example, we prove NP-hardness factor of 95/94
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