What is difference between PDA and TM?

What is difference between PDA and TM?

Answer. A PDA can only access the top of its stack, whereas a TM can access any position on an infinite tape. An automaton with access to two stacks rather than just one can simulate a TM and thus has equivalent computational power.

How do you show a language is Turing recognizable?

Prove that the language it recognizes is equal to the given language and that the algorithm halts on all inputs. To prove that a given language is Turing-recognizable: Construct an algorithm that accepts exactly those strings that are in the language. It must either reject or loop on any string not in the language.

Which language is accepted by Turing machine?

A language is recursively enumerable (generated by Type-0 grammar) if it is accepted by a Turing machine. A TM decides a language if it accepts it and enters into a rejecting state for any input not in the language. A language is recursive if it is decided by a Turing machine.

Is the empty language Decidable?

Languages (1) and (2) are, respectively, {0, 1}* and the empty language, both of which are decidable (so there are TMs that always halt that accept those languages).

Are all recognizable languages Decidable?

Note: Decidable languages are closed under complementation, but recognizable languages are not. – Write-only means (a) symbol on output tape does not affect transitions, and (b) tape head only moves right. Note M need not enumerate strings in order.

Are Decidable languages closed under intersection?

Intersection Both decidable and Turing recognizable languages are closed under intersection. – Decidable languages are closed under complementation. To design a machine for the complement of a language L, we can simulate the machine for L on an input. If it accepts then accept and vice versa.

Is P closed under complementation?

P is closed under complement. For any P-language L, let M be the TM that decides it in polynomial time. We construct a TM M’ that decides the complement of L in polynomial time: M’= “On input : Since M runs in polynomial time, M’ also runs in polynomial time.

What is decidable and undecidable problems?

A problem is said to be Decidable if we can always construct a corresponding algorithm that can answer the problem correctly. It is also important to know that these problems are termed as Turing Decidable since a Turing machine always halts on every input, accepting or rejecting it.

What makes a problem Undecidable?

In computability theory, an undecidable problem is a type of computational problem that requires a yes/no answer, but where there cannot possibly be any computer program that always gives the correct answer; that is, any possible program would sometimes give the wrong answer or run forever without giving any answer.

Why is the halting problem Undecidable?

Example: the halting problem in computability theory Alan Turing proved in 1936 that a general algorithm running on a Turing machine that solves the halting problem for all possible program-input pairs necessarily cannot exist. Hence, the halting problem is undecidable for Turing machines.

Is Undecidable a word?

Incapable of being decided, settled, or solved.

How do you spell Undecidable?

Correct spelling for the English word “undecidable” is [ˌʌndɪsˈa͡ɪdəbə͡l], [ˌʌndɪsˈa‍ɪdəbə‍l], [ˌʌ_n_d_ɪ_s_ˈaɪ_d_ə_b_əl] (IPA phonetic alphabet).

What does Decidable mean?

capable of being decided

What does indecisive mean?

1 : marked by or prone to indecision : irresolute an indecisive state of mind. 2 : not decisive : inconclusive an indecisive battle.

What is indecisiveness a sign of?

Abstract. Indecisiveness is defined as a maladaptive trait resulting in difficulty making decisions across time and situations. Indecisiveness is positively correlated with measures of anxiety, worry, and depression and has been listed as a symptom of Major Depressive Disorder for decades.

Is there a disorder for being indecisive?

Aboulomania (from Greek a– ‘without’, and boulē ‘will’) is a mental disorder in which the patient displays pathological indecisiveness. It is typically associated with anxiety, stress, depression, and mental anguish, and can severely affect one’s ability to function socially.

Is indecisiveness a symptom of ADHD?

For those with ADHD, indecisiveness is often a real problem. The inability to make a decision can leave them paralyzed. They might do nothing because they don’t have a clear idea of which path to follow. The inability to make a decision might stem from executive functioning impairments.

Does ADHD make it hard to make decisions?

Making decisions is a challenge for adults with ADHD. The symptom of distraction is one reason decision-making is difficult. Adults with ADHD get distracted by both external cues (such as background noise) and internal cues (such as thoughts and feelings).

How do you treat indecisiveness?

Stop Being Indecisive

1. Pay Attention to Your Emotions.
2. Take Your Time.
3. Think Strategically.
4. Ask Who You’re Trying to Please.
5. Banish Your Perfection Mindset.
6. Let Go of Bad Decisions.
7. Visualize Possible Outcomes.

Is indecisiveness a symptom of bipolar?

Patients with bipolar disorder may experience an exacerbation in executive dysfunction when manic or depressed, which may lead to a tendency to ruminate because of a failure to inhibit self-focused thoughts of a positive or negative nature.

What is a bipolar rage?

“Bipolar anger is impulsive, intense, erratic, and explosive. It is being asked a simple question and responding with irrational anger and/or irritation. It is lashing out, for no logical reason, on those that love and care for you.

What is the root cause of indecisiveness?

Fear of making the wrong decision is one of the reasons that many people hesitate when faced with a choice. You may be afraid of failure or even the consequences of success. You may worry what other people will think about you. Perfectionism may be getting in your way.

What are the 7 steps in decision making?

1. Step 1: Identify the decision. You realize that you need to make a decision.
2. Step 2: Gather relevant information.
3. Step 3: Identify the alternatives.
4. Step 4: Weigh the evidence.
5. Step 5: Choose among alternatives.
6. Step 6: Take action.
7. Step 7: Review your decision & its consequences.

Is indecisiveness part of OCD?

Individuals with obsessive-compulsive disorder (OCD) often exhibit indecisiveness, pathological doubt, and avoidance of uncertainty (Rasmussen and Eisen, 1992; Reed, 1985; Tolin et al., 2003), even when the task at hand is unrelated to their primary symptomatology (Hamilton, 1957).

Is list making a sign of OCD?

Compulsive list-making is a common symptom of OCD.

Is procrastination a sign of OCD?

On procrastination as a symptom of OCD “It’s funny — procrastination can be a symptom of OCD in the sense that because you know a project will require so much of your effort, and you’re so frightened of screwing up, it’s easy to just keep putting it off and putting it off and putting it off. …