- Effective decidability(logic and computability theory)
- The quality of being able to determine whether something is true or false using a clear, mechanical procedure that will always give you an answer eventually.
- Natural numbers(mathematics)
- The counting numbers: 1, 2, 3, 4, and so on (sometimes including 0, depending on context).
- Relation (in mathematics)(logic and mathematics)
- A connection or rule that links items together—for example, 'is greater than' is a relation that can connect pairs of numbers.
- Tuple(mathematics and logic)
- An ordered list or sequence of items—for example, (3, 5, 7) is a tuple of three numbers.
- algorithm(Philosophy of computation and information)
- A fundamental concept in information and computation theory, accepted as a primitive notion alongside data set
- computable set(Extends the definition of primitive recursive relation via Church's Thesis)
- A relation R is computable just in case there is an algorithm for deciding whether R(n-vector) holds that always returns an answer after a finite, although potentially unbounded, number of steps