Definitions
1.AdjectiveCapable of being computed, or enumerated.
2.AdjectiveOf a problem, solvable by a Turing machine or any thereto Turing-equivalent model; Turing-computable.
3.Adjectiveof a number, able to be approximated to arbitrary precision by a computable function
4.AdjectiveOf a countably infinite set, having a computable indicator function.