PROPERTIES OF STOCHASTIC SYNTAX-DIRECTED TRANSLATION SCHEMATA

Stochastic syntax-directed translation schemata describe both the syntactic structure and the probability distribution of stochastic mappings between contextfree languages. The relationship between stochastic syntax-directed translation schemata and stochastic grammars and automata are presented by proving that a stochastic pushdown transducer can be constructed to define the same translations as a simple schema, and that the simple schema are characterized by stochastic contextfree grammars. Asymptotic properties of linear schemata are established by the theory of Markov chains. Since stochastic translations contain both input and output strings, their information content can be described. Equations are developed for both the information content and the rate of stochastic translations. © 1979 Plenum Publishing Corporation.