A stateless k-head two-way deterministic finite automaton (k-head 2DFA), has only one state, hence the designation stateless. Its transitions depends solely on the symbols currentl...
We propose a new way to implement (general) computing devices with unbounded memory. In particular, we show a procedure to implement automata with unbounded stack memory, push-down...
We observe that pushdown tree automata (PTAs) known in the literature cannot express combinations of branching and pushdown properties. This is because a PTA processes the children...
We study languages of nested trees--structures obtained by augmenting trees with sets of nested jump-edges. These graphs can naturally model branching behaviors of pushdown program...
An automata theory course can be taught in an interactive, hands-on manner using a computer. At Duke we have been using the software tool JFLAP to provide interaction and feedback...