Probabilities in context-free programmed grammars,

TLDR: Context-free programmed grammars with probabilities attached to the 'go-to' fields are studied as realistic models for syntactical information sources and a first-order Markov approximating source is obtained.

Abstract: : Context-free programmed grammars with probabilities attached to the 'go-to' fields are studied as realistic models for syntactical information sources. The model is formally defined and examples of its output are given. Simplifications that follow from the imposition of leftmost derivations are displayed. Source models for languages that are known to be context-free are studied, and for these a first-order Markov approximating source is obtained; standard methods are then used to calculate its entropy. (Author)