On the computing power of fuzzy Turing machines

BENJAMÍN RENÉ CALLEJAS BEDREGAL; SANTIAGO FIGUEIRA

FUZZY SETS AND SYSTEMS

Elsevier

Año: 2008 vol. 159 p. 1072 - 1083

0165-0114

We work with fuzzy Turing machines (FTMs) and we study the relationship between this computational model and classical recursion concepts such as computable functions, recursively enumerable (r.e.) sets and universality. FTMs are first regarded as "acceptors". It has recently been shown by J.Wiedermann that "these machines have more computational power than classical Turing machines". Still, the context in which this formulation is valid has an unnatural implicit assumption. We settle necessary and sufficient conditions for a language to be e, by embedding it in a fuzzy language recognized by a tm. We do the same thing for n-r.e. set. It is shown that there is no universal fuzzy machine, and "universality" is analyzed for smaller classes of FTMs. We argue for a definition of computable fuzzy function, when FRMs are understood as "transducers". It is shown that, in this case, our notion of computable fuzzy function coincides with the classical one.