We show that any language recognized by an NC 1 circuit (fan-in 2, depth O (logn)) can be
recognized by a particular type of width 5 polynomial-size branching program. As any …

We give several characterizations, in terms of formal logic, semigroup theory, and operations
on languages, of the regular languages in the circuit complexity class AC 0, thus answering …

A syntactic read-k-times branching program has the restriction that no variable occurs more
than k times on any path (whether or not consistent) of the branching program. We first …

A new model, non-uniform deterministic finite automata (NUDFA's) over general finite
monoids, has recently been developed as a strong link between the theory of finite automata …

We show that every language L in the class ACC can be recognized by depth-two
deterministic circuits with a symmetric-function gate at the root and 2^\log^ O (1) n AND …

In order to study circuit complexity classes within NC 1 in a uniform setting, we need a
uniformity condition which is more restrictive than those in common use. Two such …

For a nondeterministic polynomial-time Turing machine M and an input string x, the leaf
string of M on x is the 0-1-sequence of leaf-values (0 approximately reject, 1 approximately …

The results of Cook and Karp ([K],[C]) aroused considerable interest for at least two reasons.
First, the answer to a long-standing open question which had seemed peculiar to automata …

An important goal of the theory of computation is the classification of languages according to
computational difficulty. Classes such as P, NP, and LOGSPACE provide a natural …

AaSTRACr There are languages which can be recognized by a deterministic (k+ l)-headed
one-way finite automaton but which cannot be recognized by a k-headed one-way …