A Formalization of Transition Diagram Systems
Journal of the ACM (JACM)
Transition network grammars for natural language analysis
Communications of the ACM
Design of a separable transition-diagram compiler
Communications of the ACM
Compositions of n tree transducers
STOC '72 Proceedings of the fourth annual ACM symposium on Theory of computing
Intercalation theorems for stack languages
STOC '69 Proceedings of the first annual ACM symposium on Theory of computing
The Mathematical Theory of Context-Free Languages
The Mathematical Theory of Context-Free Languages
Journal of Computer and System Sciences
Generalized2 sequential machine maps
Journal of Computer and System Sciences
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We develop intercalation lemmas for the computations of the top-down tree transducers defined by Rounds and Thatcher. These lemmas are used to prove necessary conditions for languages, all of whose strings are of exponential length, to be tree transducer languages. The language {ww: w@?{a, b}^*, |w|=2^n, n=0}, which is generable by the composition of two transducers, is shown not to be generable by one. The proof technique applies to bottom-up transducers as well. The results are related to some subclasses of Woods' Augmented Transition Networks characterized elsewhere in terms of tree transducer languages.