=ADD= =reftype= 14 =number= 01-27 =url= ftp://ftp.risc.uni-linz.ac.at/pub/techreports/2001/01-27.ps.gz =year= 2001 =month= 12 =author= Rolletscheck; Heinrich =title= Computability Theory (Lecture Notes) =abstract= These are lecture notes for a course on computability theory. The main topics are: \item{$\bullte$}Definition of the basci concepts (partial recursive, recursive and primitive recursive functions, recursive, primitive recursive and recursively enumerable sets) based on a primitive programming language. \item{$\bullet$}Proof that many intuitively computable functions are indeed partial recursive, and that the defined computability classes are closed under many operations. \item{$\bullet$}Construction of universal functions, S-m-n-theorem, diagonalization method for proving negative results, basic properties of recursively enumerable sets. \item{$\bullet$}Alternative ways to define the class of partial recursive functions ($\mu$-recursion, Turing machines, Markov algorithms). \item{$\bullet$}Undecidability results, undecidability proofs by reduction, results on enumeration, fixed-point theorem. \item{$\bullet$}Basic theory of reducibility relations.