ENTROPY OF UNDERDETERMINED SEQUENCES UNDER CONSTRAINTS TO SPECIFICATIONS. | Prikladnaya Diskretnaya Matematika - Applied Discrete Mathematics. 2008. № 1(1).

Sequences of undetermined symbols are considered. Every such symbol is associated with a set of completely defined symbols,one of which can be used to replace (specify) the former. The specification of an undetermined sequence is the result of replacingall of its symbols by some specifications. We consider the classes of all undetermined sequences which have given length andgiven frequencies of symbols appearance. The combinatorial entropy of the class is logarithm of the minimum cardinality of a setwhich contains a specification for each sequence of the class. If some constraints to parameters of specifications are introducedwe say about the constrained entropy. The article contains the fairly sharp estimates of the constrained combinatorial entropy.