The Turing reduction relation is transitive meaning that if $A\leq_T B$ and $B\leq_T C$ then $A\leq_T C$. The proof I have seen for this is let $e_0$ be an index of $A$ as $B$-computable set ($A=\Phi^B_e$) and let $e_1$ be an index for $B$ as $C$-computable set. To show that $A$ is $C$ computable I simply replace in the program $e_0$ the instances in which it calls the oracle with a computation of $B$ relative to $C$ (let $d$ be the index for this program). Since this proof is rather hand-wavy I wanted to know if the index of this program depends in any way to the sets $A,B,C$ or does it only depend on $e_0$ and $e_1$. In other words let $E,F,G$ be sets such that $E=\Phi_{e_0}^F$ and $F=\Phi_{e_1}^G$ then is $E=\Phi^G_d$? I'm pretty sure that $d$ cannot be any index such that $A=\Phi^C_d$.
2026-03-27 02:07:43.1774577263
Transitivity of Turing reduction
95 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
There are 1 best solutions below
Related Questions in RECURSION
- Solving discrete recursion equations with min in the equation
- Recognizing recursion relation of series that is solutions of $y'' + y' + x^2 y = 0$ around $x_0 = 0$.
- Ackermann Function for $(2,n)$
- Primitive recursive functions of bounded sum
- Ackermann Function for $f(2,n)$ as compared to $f(5,1)$
- Determinant of Block Tridiagonal Matrix
- In how many ways can the basketball be passed between four people so that the ball comes back to $A$ after seven passes? (Use recursion)
- Finding a recursive relation from a differential equation.
- A recursive divisor function
- Are these numbers different from each other?
Related Questions in COMPUTABILITY
- Are all infinite sets of indices of computable functions extensional?
- Simple applications of forcing in recursion theory?
- Proof of "Extension" for Rice's Theorem
- How to interpret Matiyasevich–Robinson–Davis–Putnam in term of algebraic geometry or geometry?
- Does there exist a weakly increasing cofinal function $\kappa \to \kappa$ strictly below the diagonal?
- Why isn't the idea of "an oracle for the halting problem" considered self-contradictory?
- is there any set membership of which is not decidable in polynomial time but semidecidable in P?
- The elementary theory of finite commutative rings
- Is there any universal algorithm converting grammar to Turing Machine?
- Is the sign of a real number decidable?
Related Questions in TURING-MACHINES
- Has the effort to confirm $\Sigma(5)$ and the search for new champions with $6$ states been stopped?
- Pop-up cards Turing complete?
- How does a cellular automaton "know" when to halt?
- Is the halting problem also undecideable for turing machines always writing a $1$ on the tape?
- Proof of "Extension" for Rice's Theorem
- Do we need enumeration to find the maximal number of steps a special Turing machine can make?
- Deciding wether a language is regular, in the arithmetic hierarchy
- Can a machine exist making more steps than the current record, which is no busy beaver?
- Can the halting problem for bounded Turing machines be efficiently decided?
- Can we efficiently determine the function $f(n,s)$?
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?
It is uniform. Given $e_0$ and $e_1,$ we have $d=f(e_0,e_1)$, where $f$ is a fixed computable function. All $f$ does is look through the oracle computation $\Phi^{\_}_{e_0}$ and replace all calls to the oracle with calls to $\Phi_{e_1}^{\_}$ and return the index of that resulting oracle computation.