Turing and local competition questions?

I came across the question of the practical computer knowledge Olympiad.

For A ⊆ ℕ, we have a = deg T (A) = {B | B ≡ T A} and D = {deg T (A) | A ⊆ ℕ}. For (D, ≤), which has A ≤ T B if a ≤ b. Which of the following values ​​is incorrect:

  • (D, ≤) is a distribution lattice

  • (D, ≤) is limited (has a minimum and a maximum)

  • (D, ≤) is a half-diffusion lattice. (maybe I phrased this expression poorly, sorry)

  • The maximum elements (D, ≤) are the degree of the stop problem.

I think deg T stands for Turing Degree and < T stands for Turing Reduction .

Who can give me a hint for these options, we want to check the answer the sheet that wrote (1) is correct?

+3
source share

All Articles