According to Knuth's notes (see Slide 3), an algorithm, by definition, satisfies the following five properties:
Finiteness: Terminates after a finite number of steps.
Definiteness: Each step is precisely defined.
- Input: Has zero or more inputs.
- Output: Has one or more outputs, each of which has a specified relation to the inputs.
- Effectiveness: All operations are sufficiently basic that they may be performed exactly and in finite length.
Is there a term for something that satisfies steps 2-5 and also 1 with the word finite replaced by countable?