Diagonalization proof

A matrix is normal if and only if either pre-multiplying or post-multiplying it by its conjugate transpose gives the same result. It turns out that a matrix is normal if and only if it is unitarily similar to a diagonal matrix. In other words, not only normal matrices are diagonalizable, but the change-of-basis matrix used to perform the ...

Before I wrote down the proof of the fixed point theorem in Sipser's style (i.e. the quine-like proof above), I had thought it would come out basically the same way as the standard diagonalization proof. However, now that I look at the proofs side-by-side, I am having trouble actually picking out connections between them (e.g.Nov 5, 2020 · Here the diagonalization means that the Hamiltonian is unitarily equivalent to the second quantization of a one-particle Hamiltonian, up to a constant. In many studies of quadratic Hamiltonians, Bogoliubov transformations were con- ... Proof. It is sufficient to show that F is bijective. For each f ∈ H , we put G(f) :=The diagonalization proof does not go down any list. It merely asserts the existence of a number whose n'th digit is different from the n'th digit of the n'th number in the list. Such a number must clearly exist since the sequence of partial decimal expansions forms a Cauchy sequence.In the end, whether you accept diagonalization or not is up to you. The majority of theoreticians in the world seem to accept it; indeed, not accepting it can earn a bit of ridicule. But there’s no reason you need to bow to their logic… When all is said and done, a proof is just a social construct, a particular kind of persuasive argument.that p(A) = 0. This completes the proof of the Cayley-Hamilton theorem in this special case. Step 2: To prove the Cayley-Hamilton theorem in general, we use the fact that any matrix A ∈ Cn×n can be approximated by diagonalizable ma-trices. More precisely, given any matrix A ∈ Cn×n, we can find a sequence of matrices {A k: k ∈ N} such ...formal proof of Cantor's theorem, the diagonalization argument we saw in our very first lecture. Here's the statement of Cantor's theorem

Throughout history, babies haven’t exactly been known for their intelligence, and they can’t really communicate what’s going on in their minds. However, recent studies are demonstrating that babies learn and process things much faster than ...Lecture 30: Diagonalization Diagonalization Two matrices are called similarif S−1AS. A matrix is called diagonalizableif it is similar to a diagonal matrix. A matrix is diagonalizable if and only if it has an eigenbasis, a basis consisting of eigenvectors. Proof. If we have an eigenbasis, we have a coordinate transformation matrix S which ... The proof of this theorem will be presented explicitly for n = 2; the proof in the general case can be constructed based on the same method. Therefore, let A be 2 by 2, and denote its eigenvalues by λ 1 and λ 2 and the corresponding eigenvectors by v 1 and v 2 (so that A v 1 = λ 1 v 1 and A v 2 = λ 2 v 2 ).1. BTM is also undecidable, with a similar diagonalization proof. Suppose the Turing machine M M decided BTM. Define a Turing machine T T that, on input x x an encoding of a Turing machine, it computes the encoding yx y x of a Turing machine which runs the Turing machine encoded by x x on input x x; if M(yx) = 1 M ( y x) = 1 then T T …Problem Five: Understanding Diagonalization. Proofs by diagonalization are tricky and rely on nuanced arguments. In this problem, we'll ask you to review the formal proof of Cantor’s theorem to help you better understand how it works. (Please read the Guide to Cantor's Theorem before attempting this problem.)

6 thg 5, 2009 ... Georg Cantor also came up with this proof that you can't match up the reals with the naturals. ... diagonalisation argument. And for those Star ...The 1981 Proof Set of Malaysian coins is a highly sought-after set for coin collectors. This set includes coins from the 1 sen to the 50 sen denominations, all of which are in pristine condition. It is a great addition to any coin collectio...Proof. First, we prove the “only if” part: if \(A\) is diagonalizable, it has \(n\) linearly independent eigenvectors. Observe that if \(P\) is any \(n\times n\) matrix with columns \(\mathbf{v}_1,\dots,\mathbf{v}_n,\) thenMar 4, 2018 · Diagonalization proof: A TM not decidable Sipser 4.11 Assume, towards a contradiction, that M ATM decides A TM Define the TM D = "On input <M>: 1. Run M ATM on <M, <M>>. 2. If M ATM accepts, reject; if M ATM rejects, accept." Consider running D on input <D>. Because D is a decider: ! either computation halts and accepts …!

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Diagonalization Examples Explicit Diagonalization Theorem 5.2.3: With Distinct Eigenvalues Let A be a square matrix A, of order n. Suppose A has n distincteigenvalues. Then I the corresponding eigenvectors are linearly independent I and A is diagonalizable. Proof. I The second statement follows from the rst, by theorem 5.2.2. So, we prove the ... diagonalization; proof-theory; provability; Share. Cite. Follow edited Apr 4, 2021 at 21:16. Robin Saunders. asked Apr 2, 2021 at 16:14. Robin Saunders Robin Saunders. 884 6 6 silver badges 13 13 bronze badges $\endgroup$ 4 $\begingroup$ I don't understand your second paragraph. First of all, it seems to assume $\mathcal{T}$ is …Diagonalization is the process of finding the above and . Diagonalizing a matrix makes many subsequent computations easier. One can raise a diagonal matrix to a power by simply raising the diagonal entries to that power. The determinant of a diagonal matrix is simply the product of all diagonal entries.Why is the language containing the Turing machines which only accept their own encoding not applicable to the diagonalization proof? 0. Turing recognizability and Reduction Mapping on pairs of related Turing machines. 1.

Problem Five: Understanding Diagonalization. Proofs by diagonalization are tricky and rely on nuanced arguments. In this problem, we'll ask you to review the formal proof of Cantor’s theorem to help you better understand how it works. (Please read the Guide to Cantor's Theorem before attempting this problem.) Sep 16, 2021 · Moral: A proof \relativizes" if a) you (the prover) enumerate over Turing Machines, and b) use a Universal Turing Machine to simulate other Turing Machines. Observation Any diagonalization proof relativizes. Example Given a time function t;suppose we want to show DTIME O(t(n)) ( DTIME O(t(n)2) for any oracle O:We would simply go …–The same diagonalization proof we used to prove R is uncountable •L is uncountable because it has a correspondence with B –Assume ∑* = {s 1, s 2, s 3 …}. We can encode any language as a characteristic binary sequence, where the bit indicates whether the corresponding s i is a member of the language. Thus, there is a 1:1 mapping. Think of a new name for your set of numbers, and call yourself a constructivist, and most of your critics will leave you alone. Simplicio: Cantor's diagonal proof starts out with the assumption that there are actual infinities, and ends up with the conclusion that there are actual infinities. Salviati: Well, Simplicio, if this were what Cantor ...Diagonalization: infinite sequences over {0,1}. Theorem. The set S of all ... How do we use H to construct a decider. D for ATM? 17 / 26. Page 45. Proof. Proof.Gödel’s two incompleteness theorems are among the most important results in modern logic, and have deep implications for various issues. They concern the limits of provability in formal axiomatic theories. The first incompleteness theorem states that in any consistent formal system \ (F\) within which a certain amount of arithmetic can be ...Sep 3, 2023 · We will prove the proposition for upper triangular matrices. The proof is by induction on the dimension of the matrix. A matrix is diagonal by definition and normal because the product of scalars is commutative. Now, suppose that upper triangular matrices are normal if and only if they are diagonal. We need to prove that the claim is true for …Today we will give an alternative perspective on the same proof by describing this as a an example of a general proof technique called diagonalization. This techniques was introduced in 1873 by Georg Cantor as a way of showing that the (in nite) set of real numbers is larger than the (in nite) set of integers. Mar 6, 2022 · Mar 5, 2022. In mathematics, the diagonalization argument is often used to prove that an object cannot exist. It doesn’t really have an exact formal definition but it is easy to see its idea by looking at some examples. If x ∈ X and f (x) make sense to you, you should understand everything inside this post. Otherwise pretty much everything. Diagonalization: infinite sequences over {0,1}. Theorem. The set S of all ... How do we use H to construct a decider. D for ATM? 17 / 26. Page 45. Proof. Proof.Ladner's Theorem states that if P ≠ NP, then there is an infinite hierarchy of complexity classes strictly containing P and strictly contained in NP. The proof uses the completeness of SAT under many-one reductions in NP. The hierarchy contains complexity classes constructed by a kind of diagonalization, each containing some language to which ...

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Dec 24, 2014 · 2 Answers. If you consider A, B A, B as quadratic forms, then, of course, they are simultaneously diagonalizable. That is, there is an invertible S S s.t. STBS = I,STAS = D S T B S = I, S T A S = D where D D is a diagonal matrix. Proof: diagonalize B B and B−1/2AB−1/2 B − 1 / 2 A B − 1 / 2. Since B−1/2AB−1/2 B − 1 / 2 A B − 1 / ...Question regarding Two sets with Equal Cardianlity. Two sets A and B has the same cardinality if, 1)There is a one to one correspondence between the sets. 2)If for every element in B there exists an element in A (no elements in either set is left out) (ie)onto . I can understand why satisfying these 2 properties leads to the conclusion that ...A heptagon has 14 diagonals. In geometry, a diagonal refers to a side joining nonadjacent vertices in a closed plane figure known as a polygon. The formula for calculating the number of diagonals for any polygon is given as: n (n – 3) / 2, ...Diagonalization is the process of transforming a matrix into diagonal form. Not all matrices can be diagonalized. A diagonalizable matrix could be transformed into a …if the first digit of the first number is 1, we assign the diagonal number the first digit 2. otherwise, we assign the first digit of the diagonal number to be 1. the next 8 digits of the diagonal number shall be 1, regardless. if the 10th digit of the second number is 1, we assign the diagonal number the 10th digit 2.formal proof of Cantor's theorem, the diagonalization argument we saw in our very first lecture. Here's the statement of Cantor's theoremDiagonalization proof: A TM not decidable Sipser 4.11 Assume, towards a contradiction, that it is. I.e. let M ATM be a Turing machine such that for every TM M and every string w, • Computation of M ATM on <M,w> halts and accepts if w is in L(M). • Computation of M ATM on <M,w> halts and rejects if w is not in L(M). If M 1 is TM with L(MDiagonalization of Symmetric Matrices Let A 2Rn n be a symmtric matrix. Thm 1. Any two real eigenvectors pertaining to two distinct real eigenvalues of A are orthogonal. Proof: Let 1 and 2 be distinct eigenvalues of A, with Av 1 = 1 v 1; Av 2 = 2 v 2: so that 1 vT 2 v 1 = v T 2 (Av 1) = (Av 2) v 1 = 2 v T 2 v 1: This implies ( 2 1) vT 2 v 1 = 0 ...

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$\begingroup$ The idea of "diagonalization" is a bit more general then Cantor's diagonal argument. What they have in common is that you kind of have a bunch of things indexed by two positive integers, and one looks at those items indexed by pairs $(n,n)$. The "diagonalization" involved in Goedel's Theorem is the Diagonal Lemma.Jun 23, 2020 · 5.5 Similarity and Diagonalization In Section 3.3 we studied diagonalization of a square matrix A, and found important applications (for example to linear dynamicalsystems). We can nowutilize the concepts of subspace, basis, and dimension ... Proof. We use induction on k. If k =1, then {x1}is independent because x1 6=0. In …Diagonalization is the process of finding the above and . Diagonalizing a matrix makes many subsequent computations easier. One can raise a diagonal matrix to a power by simply raising the diagonal entries to that power. The determinant of a diagonal matrix is simply the product of all diagonal entries.In the end, whether you accept diagonalization or not is up to you. The majority of theoreticians in the world seem to accept it; indeed, not accepting it can earn a bit of ridicule. But there’s no reason you need to bow to their logic… When all is said and done, a proof is just a social construct, a particular kind of persuasive argument.Here’s Cantor’s proof. Suppose that f : N ! [0;1] is any function. Make a table of values of f, where the 1st row contains the decimal expansion of f(1), the 2nd row contains the …However, remember that each number ending in all zeroes is equivalent to a closely-related number ending in all 1's. To avoid complex discussion about whether this is or isn't a problem, let's do a second diagonalization proof, tweaking a few details. For this proof, we'll represent each number in base-10. So suppose that (0,1) is countable.If such a proof works for n = 4, then it's a better answer for this question than the n = 3 one, because the simplest proof for n = 4 is much simpler than the simplest proof for n = 3. Using character theory, any group of order 4 is abelian since the only way to write 4 as a sum of squares is 4 = 12 + 12 + 12 + 12.…it seems to me that that 𝜑(n) ≥ Kn is the only estimate that can be derived from a generalization of the proof for the unsolvability of the Entscheidungsproblem. It appears that Gödel also recognized the simple extension of the halting theorem’s diagonalization proof to finite cases. Verification is the hardest problem in computer ...Today we will give an alternative perspective on the same proof by describing this as a an example of a general proof technique called diagonalization. This techniques was introduced in 1873 by Georg Cantor as a way of showing that the (in nite) set of real numbers is larger than the (in nite) set of integers.Structure of a diagonalization proof Say you want to show that a set is uncountable 1) Assume, for the sake of contradiction, that is countable with bijection 2) “Flip the diagonal” to construct an element such that for every 3) Conclude that is not onto, contradicting assumption Proof: Assume for contradiction that the halting problem is decidable; (The halting problem is unsolvable) HALT TM is undecidable we will obtain a contradiction using the diagonalization technique An alternative proof: Basic idea: DIAGONALIZATION PROOF 22 H M w YESMhalts onw M doesn’t halt on NO w Suppose that is decidable HALT TM … ….

Cantor's diagonal proof is precisely proof of the fact that the rectangles never become squares. That's just a very straightforward ...Induction on n n the size of the matrix. See A A as a self-adjoint operator. Prove that every self-adjoint operator is diagonalizable in an orthonormal basis. Trivial for n = 1 n = 1. Assume true for n − 1 n − 1. Then take a n × n n × n hermitian matrix. Take an eigenvalue λ λ and a corresponding eignevector x x of norm 1 1.The proof technique is called diagonalization, and uses self-reference. Goddard 14a: 2. Cantor and Infinity The idea of diagonalization was introduced by Proving Undecidability Through Diagonalization Recall: A TM = { M,w |M is a TM and M accepts w} Theorem The language A TM is undecidable. Proof. Assume to the contary that TM H decides A TM. Create TM D as follows: It runs H on M, M . If H accepts, reject. If H rejects, accept.Nov 21, 2016 · Question about Cantor's Diagonalization Proof. My discrete class acquainted me with me Cantor's proof that the real numbers between 0 and 1 are uncountable. I understand it in broad strokes - Cantor was able to show that in a list of all real numbers between 0 and 1, if you look at the list diagonally you find real numbers that are not …Recipe: Diagonalization. Let A be an n × n matrix. To diagonalize A : Find the eigenvalues of A using the characteristic polynomial. For each eigenvalue λ of A , compute a basis B λ for the λ -eigenspace. If there are fewer than n total vectors in all of the eigenspace bases B λ , then the matrix is not diagonalizable.When we feel love and kindness toward others it not only makes others feel loved and cared for, it helps us al When we feel love and kindness toward others it not only makes others feel loved and cared for, it helps us also to develop inner...Cantor's diagonal proof is precisely proof of the fact that the rectangles never become squares. That's just a very straightforward ... Diagonalization proof, The proof will be by diagonalization, like what is used to prove the undecidability of the Halting Problem. Speci cally, we want to nd TM D such that: 1. D runs in time O(g(n)) 2. L(D) 6= L(M) for every TM M that runs in time f(n). First recall how (in cs121) an undecidable problem is obtained via diagonalization. x 1 x 2 x 3::: M 1 0 M 2 1::: 0, The Arzelà–Ascoli theorem is a fundamental result of mathematical analysis giving necessary and sufficient conditions to decide whether every sequence of a given family of real -valued continuous functions defined on a closed and bounded interval has a uniformly convergent subsequence. The main condition is the equicontinuity of the family ..., The proof of Theorem 9.22 is often referred to as Cantor’s diagonal argument. It is named after the mathematician Georg Cantor, who first published the proof in 1874. Explain the connection between the winning strategy for Player Two in Dodge Ball (see Preview Activity 1) and the proof of Theorem 9.22 using Cantor’s diagonal …, The proof is straight forward. Take I = X, and consider the two families {x x : x ∈ X} and {Y x : x ∈ X}, where each Y x is a subset of X. The subset Z of X produced by diagonalization for these two families differs from all sets Y x (x ∈ X), so the equality {Y x : x ∈ X} = P(X) is impossible., This proof shows that there are infinite sets of many different “sizes” by considering the natural numbers and its successive power sets! The “size” of a set is called is cardinality. How to Cite this Page: Su, Francis E., et al. “Cantor Diagonalization.” Math Fun Facts. <https://www.math.hmc.edu/funfacts>. References:, The diagonalization proof does not go down any list. It merely asserts the existence of a number whose n'th digit is different from the n'th digit of the n'th number in the list. Such a number must clearly exist since the sequence of partial decimal expansions forms a Cauchy sequence., This proof shows that there are infinite sets of many different “sizes” by considering the natural numbers and its successive power sets! The “size” of a set is called is cardinality. How to Cite this Page: Su, Francis E., et al. “Cantor Diagonalization.” Math Fun Facts. <https://www.math.hmc.edu/funfacts>. References: , Sep 16, 2021 · Moral: A proof \relativizes" if a) you (the prover) enumerate over Turing Machines, and b) use a Universal Turing Machine to simulate other Turing Machines. Observation Any diagonalization proof relativizes. Example Given a time function t;suppose we want to show DTIME O(t(n)) ( DTIME O(t(n)2) for any oracle O:We would simply go …, Theorem 7.2.2: Eigenvectors and Diagonalizable Matrices. An n × n matrix A is diagonalizable if and only if there is an invertible matrix P given by P = [X1 X2 ⋯ Xn] where the Xk are eigenvectors of A. Moreover if A is diagonalizable, the corresponding eigenvalues of A are the diagonal entries of the diagonal matrix D., Recipe: Diagonalization. Let A be an n × n matrix. To diagonalize A : Find the eigenvalues of A using the characteristic polynomial. For each eigenvalue λ of A , compute a basis B λ for the λ -eigenspace. If there are fewer than n total vectors in all of the eigenspace bases B λ , then the matrix is not diagonalizable. , The Cantor Diagonalization proof seems hard to grasp, and it ignites endless discussions regarding its validity. Also i have been reading similar threads here on stackexchange and im very sorry to keep beating this dead horse. Nevertheless i freely admit that i still do not understand the proof correctly. Also i'm not trying to disprove it. , Supplement: The Diagonalization Lemma. The proof of the Diagonalization Lemma centers on the operation of substitution (of a numeral for a variable in a formula): If a formula with one free variable, \(A(x)\), and a number \(\boldsymbol{n}\) are given, the operation of constructing the formula where the numeral for \(\boldsymbol{n}\) has been substituted for the (free occurrences of the ... , Contents [ hide] Diagonalization Procedure. Example of a matrix diagonalization. Step 1: Find the characteristic polynomial. Step 2: Find the eigenvalues. Step 3: Find the eigenspaces. Step 4: Determine linearly independent eigenvectors. Step 5: Define the invertible matrix S. Step 6: Define the diagonal matrix D., In set theory, Cantor's diagonal argument, also called the diagonalisation argument, the diagonal slash argument, the anti-diagonal argument, the diagonal method, and Cantor's diagonalization proof, was published in 1891 by Georg Cantor as a mathematical proof that there are infinite sets which cannot be put into one-to-one correspondence with ..., Mar 10, 2021 · Structure of a diagonalization proof Say you want to show that a set 𝑇𝑇is uncountable 1) Assume, for the sake of contradiction, that 𝑇𝑇is 2) “Flip the diagonal” to construct an element 𝑏𝑏∈𝑇𝑇such that 𝑓𝑓𝑛𝑛≠𝑏𝑏for every 𝑛𝑛 3) Conclude …, May 19, 2022 · Why is the language containing the Turing machines which only accept their own encoding not applicable to the diagonalization proof? 0. Turing recognizability and Reduction Mapping on pairs of related Turing machines. 1., I read an interesting discussion about diagonalization and diagonal methods in the debate following the question: Is the author Hofstadter cheating in his argument on completeness applying Cantor's Diagonal Proof to Gödel's (natural number) Numbering? I note from the Wikipedia article about Cantor’s diagonal argument:, The proof of Theorem 9.22 is often referred to as Cantor’s diagonal argument. It is named after the mathematician Georg Cantor, who first published the proof in 1874. Explain the connection between the winning strategy for Player Two in Dodge Ball (see Preview Activity 1) and the proof of Theorem 9.22 using Cantor’s diagonal argument. Answer, Lecture 30: Diagonalization Diagonalization Two matrices are called similarif S−1AS. A matrix is called diagonalizableif it is similar to a diagonal matrix. A matrix is diagonalizable if and only if it has an eigenbasis, a basis consisting of eigenvectors. Proof. If we have an eigenbasis, we have a coordinate transformation matrix S which ... , 5.3 Diagonalization DiagonalizationTheoremExamples Diagonalization: Theorem Theorem (7) Let A be an n n matrix whose distinct eigenvalues are 1;:::; p. a. For 1 k p, the dimension of the eigenspace for k is less than or equal to the multiplicity of the eigenvalue k. b. The matrix A is diagonalizable if and only if the sum of the , Diagonalization is the process of finding the above and . Diagonalizing a matrix makes many subsequent computations easier. One can raise a diagonal matrix to a power by simply raising the diagonal entries to that power. The determinant of a diagonal matrix is simply the product of all diagonal entries., Jul 3, 2015 · Diagonalization requires simula-tion and we don’t know how a fixed NP machine can simulate an arbitrary P machine. Also a diagonalization proof would likely relativize, that is, work even if all machines involved have access to the same additional information. Bak-er, Gill and Solovay6 showed no relativ-izable proof can settle the P …, PRACTICE PROBLEMS ON DIAGONALIZATION First recall the recipe for diagonalization. Given a matrix A, here are the steps. Step 1. Compute the characteristic polynomial det(A −λI). Then compute the eigenvalues; these are the roots of the characteristic polynomial. Step 2. For each eigenvalue λ compute all eigenvalue. This …, Variations of the halting problem. Let M M be an arbitrary Turing machine and w ∈ {0, 1}∗ w ∈ { 0, 1 } ∗ be a binary string. The language HALT = { M, w : M halts on input w} HALT = { M, w : M halts on input w } is undecidable by the famous diagonalization proof. But what happens when we either fix the Turing machine M M or the input w w?, In the end, whether you accept diagonalization or not is up to you. The majority of theoreticians in the world seem to accept it; indeed, not accepting it can earn a bit of ridicule. But there’s no reason you need to bow to their logic… When all is said and done, a proof is just a social construct, a particular kind of persuasive argument. , Nov 21, 2016 · Question about Cantor's Diagonalization Proof. My discrete class acquainted me with me Cantor's proof that the real numbers between 0 and 1 are uncountable. I understand it in broad strokes - Cantor was able to show that in a list of all real numbers between 0 and 1, if you look at the list diagonally you find real numbers that are not …, Lecture 30: Diagonalization Diagonalization Two matrices are called similarif S−1AS. A matrix is called diagonalizableif it is similar to a diagonal matrix. A matrix is diagonalizable if and only if it has an eigenbasis, a basis consisting of eigenvectors. Proof. If we have an eigenbasis, we have a coordinate transformation matrix S which ... , Structure of a diagonalization proof Say you want to show that a set is uncountable 1) Assume, for the sake of contradiction, that is countable with bijection 2) “Flip the diagonal” to construct an element such that for every 3) Conclude that is not onto, contradicting assumption , SageMath Note - Diagonalization. We demonstrate how diagonalization can be done in Sage. We start by defining the matrix to be diagonalized, and also …, There’s a lot that goes into buying a home, from finding a real estate agent to researching neighborhoods to visiting open houses — and then there’s the financial side of things. First things first., Sep 22, 2023 · Turing’s proof didn’t involve any uncomputable problem that might arise in practice—instead, it concocted such a problem on the fly. Other diagonalization proofs are similarly aloof from the real world, so they can’t resolve questions where real-world details matter. “They handle computation at a distance,” Williams said. , Jul 27, 2018 · 5.1 Diagonalization of Hermitian Matrices Definition 5.1. A matrix is said to be Hermitian if AH = A, where the H super-script means Hermitian (i.e. conjugate) transpose. Some texts may use an asterisk for conjugate transpose, that is, A∗ means the same as A. If A is Hermitian, it means that aij = ¯aji for every i,j pair. Thus, the diagonal ..., Proving Undecidability Through Diagonalization Recall: A TM = { M,w |M is a TM and M accepts w} Theorem The language A TM is undecidable. Proof. Assume to the contary that TM H decides A TM. Create TM D as follows: It runs H on M, M . If H accepts, reject. If H rejects, accept.