[PDF] Extended Regular Expressions: Succinctness and Decidability

Most modern implementations of regular expression engines allow the use of variables (also there is a β ∈ RegEx(l) with L(β) = L(α) and c(β) ≤ fc(c(α)) If no

4 déc 2012 · Answer: If A ≤m B and B is regular, it does NOT necessarily imply that A is also regular This is because the reduction function can be more than the “power” of a DFA In fact, reduction functions are re- quired only to halt on all inputs but can be perform very sophisticated computations

[PDF] Homework 10 Solutions

If A ≤m B and B is a regular language, does that imply that A is a regular language? Answer: Suppose for a contradiction that ATM ≤m ETM via reduction f

[PDF] Practice Problems for Final Exam: Solutions CS 341: Foundations of

Answer: Language B is NP-hard if for every language A ∈ NP, we have A ≤P B (b) Give the transition functions δ of a DFA, NFA, PDA, Turing machine and

[PDF] CSE105 Homework 3 - UCSD CSE

b We construct a NTM M' that decides the concatenation of L1 and L2: If A ≤m B and B is a regular language, does that imply that A is a regular language? We refer to the two languages as A and B, and TM MA and MB are the Non-

[PDF] COMP481 Review Problems Turing Machines and - Computer

If M does not halt and does not go beyond 2r squares, M∗ rejects 2 If A ≤m B and B is a regular language, does that imply that A is a regular language? NO

[PDF] Mapping Reductions

If there is a mapping reduction from language A to language B, we TM for language B Machine R YES NO Compute f f(w) w Machine H A ≤ M B H = “ On input w This means that some TMs accept regular languages and some TMs do

[PDF] Mapping reducibility and Rices theorem - MIT OpenCourseWare

of properties of Turing machine behavior (or program B ⊆ Σ 2 * be languages Then A is mapping-reducible to B, A ≤ m accepts a regular language

[PDF] Lecture 9

technique of mapping reducibilities for prove that languages are Does a TM accept a regular language? Theorem: If A ≤mB and B is decidable, then A is