Show that Turing-decidable languages are closed under the
following operations:
union
concatenation
star
Show that Turing-recognizable languages are closed under the
following operations:
union
concatenation
star
Each answer needs only be a short informal description of a
Turing Machine (but it must still be sufficiently precise so
someone could reconstruct a formal machine if needed).
i)Show that infinite decidable language has infinite decidable
subset ?
ii)Show that any infinite decidable language L has an infinite
decidable subset J with the property that L − J is also infinite.
iii. Does the statement in part i of this problem still true if
L is only recognizable ? Show or Counter example.
No Spam please.
Prove that the language L={(M, N): M is a Turing machine and N
is a DFA with L(M) =L(N)} is undecidable. You need to derive a
reduction from Atm={(M, w)|Turing machine M accepts w} to L.
(In layman's terms please, no other theorems involved)
Turing Machine and Closure Operations
Show that Turing-recognizable languages are closed under the
following operations:
union
concatenation
star
Each answer needs only be a short informal description of a
Turing Machine (but it must still be sufficiently precise so
someone could reconstruct a formal machine if needed).
Also, be careful with non-termination (when appropriate)!
Please write an example of a language that is
Turing-decidable but not Context-Free. You can just state what the
language is; no need to give a full TM algorithm for
it.
1b) Please write an example of a language that is not
Turing-decidable. You can just state what the language is; no need
to give a full TM algorithm for it.
Design a Turing Machine to construct the function f(n) = 4 [1/4
n] + 2, (that is, 2 more than 4 times the integer part of 1/4 n)
for n Element N. Do not just produce a TM, but also describe
briefly how it works. There is a TM in the Cooper notes that does
something similar. You may modify it to produce the required TM, or
produce a machine totally independently.
What is a Turing Machine? Be able to describe its parts.
Given a Turing Machine description, be able to carry out a
computation and show the resultant tape.
What is the halting problem?
Is the halting problem decidable?
What is Hoare Logic?
When proving a program correct, we must look at the initial
assertion and final assertion. What are these?
What is a loop invariant?
Can you give me a turing machine for the language c* n b*2n a*
n+2 for n>=0 . Please give the entire diagram with states,
transition function, alphabet. Can use either one-tape or two-tape
(both infinite). Describe the logic used to build the machine. Run
the TM that accepts for any string of length > 1. Also run for
string cbba.
Question ::: A Forgetful Turing Machine (FTM) operates
just like a normal Turing Machine except that, in every instruction
(it, transition) the letter written in the tape
cell is always the letter 'a', regard less of the current
state and the current letter (although the read/write head is still
allowed to move either Left or Right, according to the
instruction). What class of the languages is recognised by FTMs?
Justify the answer.
Could u explain why it is regular language?