R (complexity)
In computational complexity theory, R is the class of decision problems solvable by a Turing machine, which is the set of all recursive languages. R is often identified with the class of 'effectively computable' functions (the Church-Turing thesis).
Since we can decide any problem for which there exists a recogniser and also a co-recogniser by simply interleaving them until one obtains a result, the class is equal to .
