We show that every NP problem is polynomially equivalent to a simple combinatorial problem: the membership problem for a special class of digraphs. These classes are defined by me...
Many natural problems in computer science concern structures like graphs where elements are not inherently ordered. In contrast, Turing machines and other common models of computa...
The question of whether there is a logic that captures polynomial time is the central open problem in descriptive complexity theory. In my talk, I will review the question and the...
Abstract. We study the complexity of the isomorphism and automorphism problems for finite rings. We show that both integer factorization and graph isomorphism reduce to the problem...
Abstract. Kanazawa ([1]) has studied the learnability of several parameterized families of classes of categorial grammars. These classes were shown to be learnable from text, in th...