 
Summary: Theory of Computation
Lecture 12: Decidable Languages
Max Alekseyev
University of South Carolina
February 23, 2012
Turing Machine: Languages
Recall that a collection of strings that a TM M accepts is called
the language of M or language recognized by M, denoted L(M).
Definition
A language is Turingrecognizable (or recursively enumerable) if it
is recognized by some Turing machine.
Turing Machine: Languages
Recall that a collection of strings that a TM M accepts is called
the language of M or language recognized by M, denoted L(M).
Definition
A language is Turingrecognizable (or recursively enumerable) if it
is recognized by some Turing machine.
A TM M on an input that is not in L(M) can either reject or loop.
We distinguish TMs that never loop and call them deciders. A
decider M decides the language that it recognizes.
