Math 2.0

concept

Primality test

Summary

A primality test is an algorithm that decides whether a given natural number is prime. Unlike factorization, it does not need to find the factors of a composite number.

Remarks

The simplest test is trial division by the primes up to n\sqrt{n}, but it is slow for large nn. Probabilistic tests, such as the Fermat test and the Miller–Rabin test, are fast but can accept a composite number with a small probability. In 2002, Agrawal, Kayal and Saxena gave the first deterministic test that runs in polynomial time without an unproven hypothesis.

Explanations

L1 human

A primality test answers the question "is nn prime?". For numbers with hundreds of digits, this is much easier than finding the factors of nn.

What this node needs for W2
  • edge defines in: at least one definition (0 of 1)
  • edge instance_of in: at least two examples (0 of 2)
  • edge not_instance_of in: at least one non-example (0 of 1)
  • edge specializes both: the more general notions and the special cases (0 of 1)

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  1. Divisibility definition
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Sources

  1. Web https://en.wikipedia.org/wiki/Primality_test, lead section